What changed in this filing

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Item 8. Financial Statements and Supplementary Data

2026-02-24 compared with 2025-02-25 · 647 added, 742 removed, 1144 unchanged (55% of the section changed)

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We believe that our audits provide a reasonable basis for our opinions.

As described in Management’s Report on Internal Control over Financial Reporting, management has excluded EnLink Midstream, LLC (“EnLink”) and Medallion Midstream, LLC (“Medallion”) from its assessment of internal control over financial reporting as of December 31, 2024, because they were acquired by the Company in purchase business combinations during 2024.

We have also excluded EnLink and Medallion from our audit of internal control over financial reporting.

EnLink and Medallion are consolidated subsidiaries whose total assets and total revenues excluded from management’s assessment and our audit of internal control over financial reporting represent approximately 20% and 3% of total assets, respectively and approximately 7% and 1% of total revenues, respectively, of the related consolidated financial statement amounts as of and for the year ended December 31, 2024.

Definition and Limitations of Internal Control over Financial Reporting

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and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

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Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

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The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Acquisition of EnLink Midstream, LLC – Valuation of Pipelines, Rights-of-Way and Processing Plants

As described in Note B to the consolidated financial statements, on October 15, 2024, the Company completed the acquisition of a controlling interest in EnLink by acquiring GIP’s interest in EnLink consisting of approximately 43% of the outstanding EnLink Units for $14.90 in cash per unit and 100% of the outstanding limited liability company interests in the managing member of EnLink for $300 million, for a total cash consideration of $3.3 billion.

The acquisition resulted in the recognition of $11.4 billion of property, plant and equipment (PP&E), a significant portion of which relates to pipelines, rights-of-way, and processing plants.

The acquisition was accounted for using the acquisition method of accounting for business combinations, which requires, among other things, assets acquired and liabilities assumed to be recorded at their fair values on the acquisition date.

As disclosed by management, in order to estimate the fair value of assets acquired and liabilities assumed, management utilized valuation techniques that included discounted cash flow and cost methods.

The discounted cash flow method utilizes assumptions that include, but are not limited to, estimated future cash flows, discount rates applied to estimated future cash flows and commodity margin growth rates.

Cost methods estimate the fair value of assets based on the estimated construction or replacement cost of the assets and require the use of various inputs and assumptions.

The principal considerations for our determination that performing procedures relating to the valuation of pipelines, rights-of-way, and processing plants acquired in the acquisition of EnLink is a critical audit matter are (i) the significant judgment by management when developing the fair value estimate of the pipelines, rights-of-way, and processing plants acquired;

(ii) a high degree of auditor judgment, subjectivity, and effort in performing procedures and evaluating management’s significant assumptions related to discount rates and commodity margin growth rates used in the discounted cash flow method and estimated construction or replacement cost used in the cost method;

and (iii) the audit effort involved the use of professionals with specialized skill and knowledge.

Revenue Recognition – Liquids Commodity Sales

As described in Note A to the consolidated financial statements, the Company records revenue from liquids commodity sales when the commodity is delivered to the customer as this represents the point in time when control of the product is transferred to the customer.

Revenue is recorded based on the contracted selling price, which is generally index-based and settled daily or monthly.

The Company recognized liquids commodity sales of $25,566 million for the year ended December 31, 2025.

The principal consideration for our determination that performing procedures relating to revenue recognition for liquids commodity sales is a critical audit matter is a high degree of auditor effort in performing procedures related to the Company’s revenue recognition.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements.

These procedures included testing the effectiveness of controls relating to the acquisition accounting, including controls over management’s valuation of the pipelines, rights-of-way, and processing plants acquired.

These procedures also included, among others (i) reading the purchase agreement;

(ii) testing management’s process for developing the fair value estimate of the pipelines, rights-of-way, and processing plants acquired;

(iii) evaluating the appropriateness of the discounted cash flows and cost methods used by management;

(iv) testing the completeness and accuracy of underlying data used in the discounted cash flow and cost methods;

and (v) evaluating the reasonableness of the significant assumptions used by management related to discount rates and commodity margin growth rates used in the discounted cash flow method and the estimated construction or replacement cost used in the cost method.

Evaluating management’s assumptions related to the commodity margin growth rates involved evaluating whether the assumptions used by management were reasonable considering (i) the current and past performance of EnLink and (ii) whether the assumptions were

consistent with evidence obtained in other areas of the audit.

Professionals with specialized skill and knowledge were used to assist in evaluating (i) the appropriateness of the discounted cash flow and cost methods and (ii) the reasonableness of the assumptions related to discount rates, commodity margin growth rates, and estimated construction or replacement cost.

These procedures included testing the effectiveness of controls relating to the revenue recognition process for liquids commodity sales.

These procedures also included, among others, (i) testing revenue recognized for a sample of liquids commodity sales revenue transactions by obtaining and inspecting source documents, such as contracts, settlement statements, invoices, and payments receipts and (ii) confirming a sample of outstanding customer invoices balances as of December 31, 2025, and for confirmations not returned, obtaining and inspecting source documents, such as contracts, settlement statements, invoices, and subsequent payment receipts.

s/ PricewaterhouseCoopers LLP

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We have served as the Company’s auditor since 2007.

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and Subsidiaries

CONSOLIDATED STATEMENTS OF INCOME

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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Services and other 4,751 3,918 2,063

Total revenues (Note R)

21,698 17,677 22,387

Total revenues (Note Q) 33,629 21,698 17,677

Cost of sales and fuel (exclusive of items shown separately below) 23,373 13,311 11,929

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Transaction costs (Note B) 81 73 158

Other operating income, net (Notes B and C)

( 305 ) ( 786 ) ( 105 )

Other operating income, net (Notes A and B) ( 43 ) ( 305 ) ( 786 )

Operating income 5,741 4,989 4,072

Equity in net earnings from investments (Note O)

Other income (expense), net 53 89 ( 29 )

Equity in net earnings from investments (Note N) 386 439 202

Other income, net 146 53 89

Interest expense (net of capitalized interest of $ 68 , $ 62 and $ 43 , respectively)

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Income before income taxes 4,490 4,110 3,497

Income taxes (Note N)

( 998 ) ( 838 ) ( 528 )

Income taxes (Note M) ( 1,028 ) ( 998 ) ( 838 )

Net income 3,462 3,112 2,659

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Net income available to common shareholders $ 3,393 $ 3,034 $ 2,658

Basic EPS (Note K)

$ 5.19 $ 5.49 $ 3.85

Diluted EPS (Note K)

$ 5.17 $ 5.48 $ 3.84

Basic EPS (Note J) $ 5.43 $ 5.19 $ 5.49

Diluted EPS (Note J) $ 5.42 $ 5.17 $ 5.48

Average shares (millions)

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CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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59 ( 53 ) 155

Derivative amounts reclassified to net income, net of tax of $ 5 , $ 21 and $( 60 ), respectively

Derivative amounts reclassified to net income, net of tax of $ 1 , $ 5 and $ 21 ,

( 2 ) ( 16 ) ( 66 )

Changes in benefit plan obligations and other, net of tax of $( 2 ), $ 3 and $( 21 ), respectively

Changes in benefit plan obligations and other, net of tax of $( 3 ), $( 2 ) and $ 3 ,

Total other comprehensive income (loss), net of tax 69 ( 63 ) 75

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See accompanying Notes to Consolidated Financial Statements .

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and Subsidiaries

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Accumulated depreciation and amortization 7,628 6,339

Net property, plant and equipment (Note F)

45,935 32,697

Investments in unconsolidated affiliates (Note O)

Goodwill (Note G)

Intangible assets, net (Note G)

Net property, plant and equipment (Note E) 47,861 45,935

Investments in unconsolidated affiliates (Note N) 2,889 2,316

Goodwill (Note F) 8,058 8,091

Intangible assets, net (Note F) 2,901 3,039

Other assets 444 450

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Current liabilities

Current maturities of long-term debt (Note H)

$ 1,059 $ 484

Current maturities of long-term debt (Note G) $ 1,241 $ 1,059

Short-term borrowings (Note G) 820 —

Accounts payable 2,838 2,187

Commodity imbalances 217 260

Accrued taxes 221 215

Accrued interest 499 511

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Total current liabilities 6,365 4,719

Long-term debt, excluding current maturities (Note H)

31,018 21,183

Long-term debt, excluding current maturities (Note G) 30,755 31,018

Deferred credits and other liabilities

Deferred income taxes (Note N)

Deferred income taxes (Note M) 6,349 5,451

Other deferred credits 603 748

Total deferred credits and other liabilities 6,952 6,199

Commitments and contingencies (Note P)

Equity (Note I)

Commitments and contingencies (Note O)

Equity (Note H)

Preferred stock, $ 0.01 par value:

authorized and issued 20,000 shares at Dec.

31, 2024, and at Dec.

authorized 100,000,000 shares;

issued and outstanding 0 shares at December 31, 2025;

issued and outstanding 20,000 shares at December 31, 2024

Common stock, $ 0.01 par value:

authorized 1,200,000,000 shares;

issued 609,713,834 shares and outstanding

583,110,633 shares at Dec.

issued 609,713,834 shares and outstanding 583,093,100 shares at Dec.

issued 655,909,018 shares and outstanding 629,707,691 shares at

December 31, 2025;

issued 609,713,834 shares and outstanding 583,110,633 shares at December 31, 2024

Paid-in capital 20,961 16,354

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Treasury stock, at cost:

26,603,201 shares at Dec.

31, 2024, and 26,620,734 shares at Dec.

26,201,327 shares at December 31, 2025, and 26,603,201 shares at

December 31, 2024

( 829 ) ( 807 )

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See accompanying Notes to Consolidated Financial Statements.

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and Subsidiaries

CONSOLIDATED STATEMENTS OF CASH FLOWS

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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Depreciation and amortization 1,514 1,134 769

Equity in net earnings from investments (Note O)

( 439 ) ( 202 ) ( 148 )

Equity in net earnings from investments (Note N) ( 386 ) ( 439 ) ( 202 )

Distributions received from unconsolidated affiliates 397 390 202

Deferred income taxes (Note N)

Deferred income taxes (Note M) 957 889 829

Gain on sale of business (Note B) — ( 227 ) —

Medford settlement gain (Note C) — ( 779 ) —

Medford settlement proceeds (Note C) — 502 61

Medford settlement gain (Note A) — — ( 779 )

Medford settlement proceeds (Note A) — — 502

Other, net 35 72 83

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Accounts payable 671 114 ( 62 )

Risk-management assets and liabilities ( 58 ) 96 197

Other assets and liabilities, net ( 105 ) ( 223 ) 195

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Capital expenditures (less allowance for equity funds used during construction) ( 3,152 ) ( 2,021 ) ( 1,595 )

Cash paid for acquisitions, net of cash acquired (Note B) ( 5,829 ) ( 5,015 ) —

Cash paid for acquisitions, net of cash acquired ( 25 ) ( 5,829 ) ( 5,015 )

Proceeds from the sale of business (Note B) — 1,200 —

Purchases of and contributions to unconsolidated affiliates (Note O)

( 111 ) ( 207 ) ( 3 )

Distributions received from unconsolidated affiliates in excess of cumulative earnings

Medford settlement proceeds (Note C) — 328 39

Purchases of and contributions to unconsolidated affiliates (Note N) ( 622 ) ( 111 ) ( 207 )

Medford settlement proceeds (Note A) — — 328

Other, net 48 149 85

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Dividends paid ( 2,583 ) ( 2,313 ) ( 1,839 )

Issuance of long-term debt, net of discounts (Note H) 7,094 5,298 869

Repayment of long-term debt (Note H) ( 2,003 ) ( 1,300 ) ( 896 )

Short-term borrowings, net 820 — —

Issuance of long-term debt, net of discounts (Note G) 2,989 7,094 5,298

Debt financing costs ( 32 ) ( 67 ) ( 71 )

Repurchase of common stock (Note I) ( 159 ) — —

Repurchase of common stock (Note H) ( 75 ) ( 159 ) —

Delaware Basin JV Acquisition (Note B) ( 550 ) — —

Extinguishment of long-term debt (Note G) ( 2,979 ) ( 2,003 ) ( 1,300 )

Repurchase of EnLink's Series C Preferred Units — ( 365 ) —

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Cash paid for interest, net of amounts capitalized $ 1,732 $ 1,297 $ 653

Cash paid for income taxes, net of refunds $ 102 $ 37 $ 59

See accompanying Notes to Consolidated Financial Statements.

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and Subsidiaries

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ONEOK Shareholders' Equity

Stock Paid-in

Capital AOCL* Retained Earnings Treasury Stock Noncontrolling Interest Total Equity

Preferred Stock Common Stock Paid-in Capital AOCL* Retained Earnings Treasury Stock Noncontrolling Interests Total Equity

(Millions of dollars)

1, 2022 $ — $ 5 $ 7,214 $ ( 471 ) $ — $ ( 732 ) $ — $ 6,016

January 1, 2023 $ — $ 5 $ 7,253 $ ( 108 ) $ 50 $ ( 706 ) $ — $ 6,494

Net income — — — — 2,659 — — 2,659

Other comprehensive income — — — 75 — — — 75

Preferred stock dividends - $ 55.00 per share (Note I )

Preferred stock dividends - $ 55.00 per share

— — — — ( 1 ) — — ( 1 )

Magellan Acquisition consideration (Note B) — 1 9,061 — — — — 9,062

Common stock issued — — 9 — — 29 — 38

Common stock dividends - $ 3.74 per share (Note I )

Common stock dividends - $ 3.82 per share (Note H)

— — — — ( 1,839 ) — — ( 1,839 )

Other, net — — ( 3 ) — ( 1 ) — — ( 4 )

31, 2022 — 5 7,253 ( 108 ) 50 ( 706 ) — 6,494

December 31, 2023 — 6 16,320 ( 33 ) 868 ( 677 ) — 16,484

Net income — — — — 3,035 — 77 3,112

Other comprehensive income — — — 75 — — — 75

Preferred stock dividends - $ 55.00 per share (Note I )

Other comprehensive loss — — — ( 63 ) — — — ( 63 )

Preferred stock dividends - $ 55.00 per share

— — — — ( 1 ) — — ( 1 )

Magellan Acquisition consideration (Note B) 1 9,061 — — — — 9,062

Common stock issued — — 25 — — 42 — 67

Common stock dividends - $ 3.82 per share (Note I )

Common stock dividends - $ 3.96 per share (Note H)

— — — — ( 2,318 ) — — ( 2,318 )

Repurchase of common stock (Note H) — — — — — ( 172 ) — ( 172 )

EnLink Controlling Interest Acquisition (Note B) — — — — — — 5,076 5,076

Distributions to noncontrolling interests ( 66 ) ( 66 )

Contributions from noncontrolling interests — — — — — — 3 3

Other, net — — 9 — ( 5 ) — 7 11

31, 2023 — 6 16,320 ( 33 ) 868 ( 677 ) — 16,484

December 31, 2024 — 6 16,354 ( 96 ) 1,579 ( 807 ) 5,097 22,133

Net income — — — — 3,393 — 69 3,462

Other comprehensive loss — — — ( 63 ) — — — ( 63 )

Preferred stock dividends - $ 55.00 per share (Note I )

Other comprehensive income — — — 69 — — — 69

Preferred stock dividends - $ 13.75 per share

— — — — — — — —

Common stock issued — — ( 9 ) — — 40 — 31

Common stock dividends - $ 3.96 per share (Note I )

Common stock dividends - $ 4.12 per share (Note H)

— — — — ( 2,596 ) — — ( 2,596 )

Repurchases of common stock (Note I) — — — — — ( 172 ) — ( 172 )

Acquisition of EnLink noncontrolling interest (Note B) — — — — — — 5,076 5,076

Repurchase of common stock (Note H) — — — — — ( 62 ) — ( 62 )

EnLink Acquisition (Note B) — 1 4,377 — — — ( 4,378 ) —

Delaware Basin JV Acquisition (Note B) — — 185 — — — ( 678 ) ( 493 )

Distributions to noncontrolling interests — — — — — — ( 47 ) ( 47 )

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Other, net — — 54 — ( 3 ) — 2 53

31, 2024 $ — $ 6 $ 16,354 $ ( 96 ) $ 1,579 $ ( 807 ) $ 5,097 $ 22,133

December 31, 2025 $ — $ 7 $ 20,961 $ ( 27 ) $ 2,373 $ ( 829 ) $ 84 $ 22,569

*Accumulated other comprehensive loss

See accompanying Notes to Consolidated Financial Statements.

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AND SUBSIDIARIES

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Organization and Nature of Operations - We are a corporation incorporated under the laws of the state of Oklahoma.

Our Natural Gas Gathering and Processing segment provides midstream services to producers in the Rocky Mountain region, the Mid-Continent region, the Permian Basin region and the the North Texas region.

Our Natural Gas Gathering and Processing segment provides midstream services to producers in the Rocky Mountain region, the Mid-Continent region and the Permian Basin.

Raw natural gas is typically gathered at the wellhead, compressed and transported through pipelines to our processing facilities.

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Purity NGLs are stored or distributed to our customers, such as petrochemical companies, propane distributors, diluent users, ethanol producers, refineries and exporters.

We provide midstream services to producers of NGLs in the Rocky Mountain region, Mid-Continent region, Permian Basin and Gulf Coast region (including Louisiana) and deliver those products to the market.

We provide midstream services to producers of NGLs in the Rocky Mountain region, Mid-Continent region, Permian Basin and Gulf Coast region and deliver those products to the market.

Our primary markets include the Mid-Continent in Conway, Kansas, the Gulf Coast in Mont Belvieu, Texas, Louisiana and the upper Midwest.

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Residue natural gas is transported or stored for end users, such as large industrial customers, natural gas and electric utilities serving commercial and residential consumers and can ultimately reach international markets through liquified natural gas exports (Louisiana Gulf Coast) and cross border pipelines.

Our assets are connected to key supply areas and demand centers, including export markets in Mexico via Roadrunner and supply areas in Canada and the United States via our interstate and intrastate natural gas pipelines and Northern Border, which enables us to provide essential natural gas transportation and storage services.

Growing demand from data centers and continued demand from local distribution companies, electric-generation facilities and large industrial companies support low-cost expansions that position us well to provide additional services to our customers when needed.

Our assets are connected to key supply areas and demand centers, including export markets in Mexico via Roadrunner and supply areas in Canada and the United States via our interstate and intrastate natural gas pipelines, Northern Border and Matterhorn, which enables us to provide essential natural gas transportation and storage services.

Growing demand from data centers and continued demand from local distribution companies, electric-generation facilities and large industrial companies support capital projects and low-cost expansions that position us well to provide additional services to our customers when needed.

Our Refined Products and Crude segment is principally engaged in the transportation, storage and distribution of Refined Products and crude oil.

As a result of the EnLink Acquisitions and the Medallion Acquisition, we are also engaged in the gathering of crude oil .

Crude oil pipelines gather and transport crude oil to refineries, export facilities and demand centers.

We are also engaged in the gathering of crude oil .

Our crude oil assets are strategically located to gather, transport and store crude oil and are connected to refineries, export facilities and multiple trading and demand centers.

Throughout our distribution system, terminals play a key role in facilitating product movements and marketing by providing storage, distribution, blending and other ancillary services.

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Under this method, we consolidate all assets and liabilities of an investment on our Consolidated Balance Sheets and record noncontrolling interests for the portion of the investment we do not own.

We include all of the investment’s results of operations on our Consolidated Statement of Income and record income attributable to noncontrolling interests for the portion of the investment that we do not own.

Our noncontrolling interests for the year ended Dec.

31, 2024, are composed of approximately 57 % of outstanding EnLink Units we did not own, Series B Preferred Units and the partially owned consolidated subsidiaries of EnLink.

See Note I for disclosures of our noncontrolling interests.

We include all of the investment’s results of operations on our Consolidated Statements of Income and record income attributable to noncontrolling interests for the portion of the investment that we do not own.

As of December 31, 2025, noncontrolling interests in our Consolidated Balance Sheets related to Ascension and MBTC Pipeline.

As a result of the Delaware Basin JV Acquisition and the EnLink Acquisition, these entities are now wholly owned subsidiaries and are no longer recorded as noncontrolling interests in our Consolidated Balance Sheets as of December 31, 2025.

As of December 31, 2024, noncontrolling interests in our Consolidated Balance Sheets were

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composed of the approximately 57 % of outstanding EnLink Units we did not own, Series B Preferred Units and the partially owned consolidated subsidiaries of EnLink.

See Note H for disclosures of our noncontrolling interests.

Investments in unconsolidated affiliates are accounted for using the equity method if we have the ability to exercise significant influence over operating and financial policies of our investee.

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These amounts are recorded as investments in unconsolidated affiliates on our accompanying Consolidated Balance Sheets.

See Note O for disclosures of our unconsolidated affiliates.

See Note N for disclosures of our unconsolidated affiliates.

Distributions paid to us from our unconsolidated affiliates are classified as operating activities on our Consolidated Statements of Cash Flows until the cumulative distributions exceed our proportionate share of income from the unconsolidated affiliate since the date of our initial investment.

The amount of cumulative distributions paid to us that exceeds our cumulative proportionate share of income in each period represents a return of investment and is classified as an investing activity on our Consolidated Statements of Cash Flows.

Variable Interest Entities (VIE) - We evaluate all legal entities in which we hold an ownership interest to determine if the entity is a VIE.

Cumulative distributions paid to us from the unconsolidated affiliate that exceed our cumulative proportionate share of income from the unconsolidated affiliate in each period represents a return of investment and is classified as an investing activity on our Consolidated Statements of Cash Flows.

Variable Interest Entities (VIEs) - We evaluate all legal entities in which we hold an ownership interest to determine if the entity is a VIE.

Variable interests are ownership interests in an entity that change with changes in the fair value of the VIE’s assets.

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We continually monitor our interests in legal entities for changes in the design or activities of an entity and changes in our interests, including our status as the primary beneficiary to determine if the changes require us to revise our previous conclusions.

See Note J for our VIE disclosures.

See Note I for our VIE disclosures.

Use of Estimates - The preparation of our Consolidated Financial Statements and related disclosures in accordance with GAAP requires us to make estimates and assumptions with respect to values or conditions that cannot be known with certainty that affect the reported amounts on our Consolidated Financial Statements.

Items that may be estimated include, but are not limited to, the economic useful life of assets, fair value of assets, liabilities and equity-method investments, obligations under employee benefit plans, allowance for credit losses, expenses for services received but for which no invoice has been received, provision for income taxes, including any deferred tax valuation allowances, the results of litigation, environmental remediation and various other recorded or disclosed amounts.

Items that may be estimated include, but are not limited to, the economic useful life of assets, fair value of assets, liabilities, derivative instruments and equity-method investments, obligations under employee benefit plans, allowance for credit losses, expenses for services received but for which no invoice has been received, provision for income taxes, including any deferred tax valuation allowances, the results of litigation, environmental remediation and various other recorded or disclosed amounts.

In addition, a portion of our revenues and cost of sales and fuel are recorded based on current month prices and estimated volumes.

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Most of the contracts in our derivative portfolio are executed in liquid markets where price transparency exists.

Our financial commodity derivatives are primarily settled through a NYMEX or Intercontinental Exchange clearing broker account with daily margin requirements.

Our financial commodity derivatives are primarily settled through a NYMEX or Intercontinental Exchange clearing broker account with daily

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margin requirements.

We validate our valuation inputs with third-party information and settlement prices from other sources, where available.

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We categorize derivatives based on the lowest level input that is significant to the fair value measurement in its entirety.

See Note D for our fair value measurements disclosures.

See Note C for our fair value measurements disclosures.

Cash and Cash Equivalents - Cash equivalents consist of highly liquid investments, which are readily convertible into cash and have original maturities of three months or less.

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However, the term between customer prepayments, completion of our performance obligations, invoicing and receipt of payment due is generally not significant.

Performance Obligations and Revenue Sources - Revenue sources are disaggregated in Note S and are derived from commodity sales and services revenues, as described below:

Performance Obligations and Revenue Sources - Revenue sources are disaggregated in Note R and are derived from commodity sales and services revenues, as described below:

Commodity Sales (all segments) - We contract to deliver residue natural gas, unfractionated NGLs and/or Purity NGLs, Refined Products, condensate and crude oil to customers at a specified delivery point.

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These costs are included as a reduction to commodity sales revenue.

Gathering only contracts ( Natural Gas Gathering and Processing segment ) - Under this type of contract, we charge fees for providing midstream services, which include gathering and treating our customers’ natural gas.

Our performance obligation begins with delivery of raw natural gas to our system.

This service is treated as one performance obligation that is satisfied over time.

We use the output method based on delivery of product to our system as the measure of progress, as our services are performed simultaneously.

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Fee with POP contracts with producer take-in-kind rights ( Natural Gas Gathering and Processing segment ) - Under this type of contract, we do not control the stream of unprocessed natural gas that we receive at the wellhead due to the producer’s take-in-kind rights.

We purchase a portion of the raw natural gas stream, charge fees for providing midstream services, which include gathering, treating, compressing and processing our customer’s natural gas.

After performing these services, we return certain commodities to the producer, sell the remaining commodities and remit a portion of the commodity sales proceeds to the producer less our contractual fees.

We purchase commodities that the producer does not take-in-kind and charge fees for providing midstream services, which include gathering, treating, compressing and processing our customers’ natural gas.

After performing these services, we return certain commodities to the producer, sell any remaining commodities and remit a portion of the commodity sales proceeds to the producer less our contractual fees.

Our performance obligation begins with delivery of raw natural gas to our system.

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We use the output method based on delivery of product to our system as the measure of progress, as our services are performed simultaneously.

For transportation services under a tariff on our transportation pipelines, fees are recorded when the product reaches its destination.

For transportation services under a tariff on our transportation pipelines, fees are recorded when our delivery obligation is complete.

We have certain contracts that require counterparties to ship a minimum volume over an agreed-upon time period, which are contracted as minimum dollar or volume commitments.

Revenue pursuant to these take-or-pay contracts is initially deferred and subsequently recognized when the customers utilize their committed volumes or when the likelihood of meeting the minimum volume commitment becomes remote.

Storage contracts ( Natural Gas Liquids, Refined Products and Crude and Natural Gas Pipelines segments ) - We reserve a stated storage capacity and inject/withdraw/store commodities for our customer.

Storage contracts ( Natural Gas Liquids, Refined Products and Crude and Natural Gas Pipelines segments ) - We reserve a stated storage capacity and inject/withdraw/store commodities for our customers.

As these services represent a stand-ready obligation provided on a daily basis over the life of the agreement, the fixed capacity reservation fees are allocated and evenly recognized in revenue over the contract term.

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We use the output method based on the passage of time to measure satisfaction of the performance obligation associated with our daily stand-ready services.

Other fees are recognized in revenue as those services are provided and are dependent on the volume moved, which is at our customer’s discretion.

Other fees are recognized in revenue as those services are provided and are dependent on the volume moved, which is at our customers’ discretion.

Firm service transportation contracts ( Natural Gas Pipelines segment ) - We reserve a stated transportation capacity and transport commodities for our customer.

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If the capacity reservation fees vary solely as a contract feature, contract assets or liabilities are recorded for the difference between the amount recorded in revenue and the amount billed to the customer.

Transportation fees are recognized in revenue as those services are provided and are dependent on the volume transported by our customer, which is at our customer’s discretion.

Transportation fees are recognized in revenue as those services are provided and are dependent on the volume transported by our customer, which is at our customers’ discretion.

We use the output method based on the passage of time to measure satisfaction of the performance obligation associated with our daily stand-ready services.

Interruptible transportation contracts ( Natural Gas Pipelines segment ) - We agree to transport natural gas on our pipelines between the customer’s specified nominated-receipt and delivery points if capacity is available after satisfying firm transportation service obligations.

Interruptible transportation contracts ( Natural Gas Pipelines segment ) - We agree to transport natural gas on our pipelines between the customers’ specified nominated-receipt and delivery points if capacity is available after satisfying firm transportation service obligations.

The transaction price is based on the transportation fees times the volumes transported.

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These fees and charges are not recorded until it is probable that a significant reversal of the associated revenue will not occur.

Receivables from Customers - Substantially all of the balances in accounts receivable on our Consolidated Balance Sheet at Dec.

31, 2024, relate to customer receivables.

Substantially all of the balances in accounts receivable on our Consolidated Balance Sheet at Dec.

31, 2023, related to customer receivables, excluding the insurance receivable related to the legal proceeding described in Note P.

See Note R for our revenue disclosures.

Receivables from Customers - Substantially all of the balances in accounts receivable on our Consolidated Balance Sheets at December 31, 2025, and December 31, 2024, are related to customer receivables.

See Note Q for our revenue disclosures.

Contract Assets and Contract Liabilities - Contract assets and contract liabilities are recorded when the amount of revenue recognized from a contract with a customer differs from the amount billed to the customer and recorded in accounts receivable.

Our contract asset balances at the beginning and end of the period primarily relate to our firm service transportation contracts with tiered rates, which are not material.

Our contract liabilities primarily represent deferred revenue on Refined Products and crude transportation contracts and NGL storage contracts for which revenue is recognized over a one-year term, and deferred revenue on contributions in aid of construction received from customers for which revenue is recognized over the contract periods, which range from one year to 17 years, contract liabilities are not material.

commodities, (iii) fuel and power costs incurred to operate our own facilities that gather, process, transport and store commodities, (iv) product gains and losses and (v) an offset from the contractual fees deducted from the cost of purchased commodities under the contract types below:

Our contract asset balances at the beginning and end of the period primarily related to our firm service transportation contracts

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with tiered rates, which are not material.

Our contract liabilities at the beginning and end of the period primarily related to deferred revenue on Refined Products and crude oil transportation contracts, NGL storage contracts and contributions in aid of construction received from customers, which were not material.

Cost of Sales and Fuel - Cost of sales and fuel primarily includes (i) the cost of purchased commodities, including natural gas, NGLs, Refined Products, condensate and crude oil, (ii) fees incurred for third-party transportation, fractionation and storage of commodities, (iii) fuel and power costs incurred to operate our own facilities that gather, process, transport and store commodities, (iv) product gains and losses and (v) an offset from the contractual fees deducted from the cost of purchased commodities under the contract types below:

Fee with POP contracts with no producer take-in-kind rights (Natural Gas Gathering and Processing segment ) - We purchase raw natural gas and charge contractual fees for providing midstream services, which include gathering, treating, compressing and processing the producer’s natural gas.

After performing these services, we sell the commodities and return a portion of the commodity sales proceeds to the producer less our contractual fees.

Purchase with fee ( Natural Gas Liquids segment ) - Under this type of contract, we purchase raw, unfractionated NGLs at an index price and charge fees for providing midstream services, which may include a bundled combination of gathering, transporting and/or fractionation.

Purchase with fee ( Natural Gas Liquids and Refined Products and Crude segments ) - Under this type of contract, we purchase product at an index price and charge fees for providing midstream services, which may include a bundled combination of gathering, transporting and/or fractionation.

Operations and Maintenance - Operations and maintenance primarily includes (i) payroll and benefit costs, (ii) third-party costs for operations, maintenance and integrity management, regulatory compliance and environmental and safety, and (iii) other business-related service costs.

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Outstanding customer receivables are reviewed regularly for possible nonpayment indicators, and allowances for credit losses are recorded based upon management’s estimate of collectability, current conditions and supportable forecasts at each balance sheet date.

31, 2024, our allowance for credit losses was not material.

At December 31, 2025, our allowance for credit losses was not material.

Inventory - The values of current NGLs, natural gas, Refined Products and crude oil in storage are determined using the lower of weighted-average cost or net realizable value.

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The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and, if so, the reason for holding it.

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The table below summarizes the various ways in which we account for our derivative instruments and the impact on our Consolidated Financial Statements:

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Under certain conditions, we designate our derivative instruments as a hedge of exposure to changes in fair values or cash flows.

We formally document all relationships between hedging instruments and hedged items, as well as risk-management objectives and strategies for undertaking various hedge transactions, and methods for assessing and testing correlation and hedge effectiveness.

We specifically identify the forecasted transaction that has been designated as the hedged item in a cash flow hedge relationship.

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Cash flows from futures, forwards, options and swaps that are accounted for as hedges are included in the same category as the cash flows from the related hedged items in our Consolidated Statements of Cash Flows.

See Notes D and E for disclosures of our fair value measurements and risk-management and hedging activities, respectively.

See Notes C and D for disclosures of our fair value measurements and risk-management and hedging activities, respectively.

Property, Plant and Equipment - Our properties are stated at cost, including AFUDC and capitalized interest.

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Assets are transferred out of construction work in process when they are substantially complete and ready for their intended use.

See Note F for our property, plant and equipment disclosures.

See Note E for our property, plant and equipment disclosures.

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Impairment of Goodwill and Long-Lived Assets, Including Intangible Assets and Equity Method Investments - We assess our goodwill for impairment at least annually as of July 1, unless events or changes in circumstances indicate an impairment may have occurred before that time.

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Therefore, we periodically evaluate the amount at which we carry our equity-method investments to determine whether current events or circumstances warrant adjustments to our carrying values.

See Notes F, G and O for our disclosures and related impairment charges related to long-lived assets, goodwill and intangible assets and investments in unconsolidated affiliates, respectively.

Leases - We lease certain buildings, warehouses, office space, land and equipment, including pipeline equipment, pipeline capacity, rail cars and information technology equipment.

In addition, as a result of the EnLink Controlling Interest Acquisition, we acquired lessee arrangements that primarily include office space, compression, field equipment and land.

Acquired office space lease arrangements typically include variable lease cost related to utility expenses, which are determined based on our pro-rata share of building expenses each month and are expensed as incurred.

See Notes E, F and N for our disclosures related to long-lived assets, goodwill and intangible assets and investments in unconsolidated affiliates, respectively.

Leases - We lease certain buildings, warehouses, office space, compression, land and equipment, including pipeline equipment, pipeline capacity, rail cars and information technology equipment.

Our office space lease arrangements typically include variable lease cost related to utility expenses, which are determined based on our pro-rata share of building expenses each month and are expensed as incurred.

Our lease payments are generally straight-line and the exercise of lease renewal options, which vary in term, is at our sole discretion.

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Accordingly, portions of our Natural Gas Liquids and Natural Gas Pipelines segments follow the accounting and reporting guidance for regulated operations as defined pursuant to Financial Accounting Standards Board’s (FASB) Accounting Standards Codification 980, Regulated Operations.

During the rate-making process for certain of our assets, regulatory

authorities set the framework for what we can charge customers for our services and establish the manner that our costs are accounted for, including allowing us to defer recognition of certain costs and permitting recovery of the amounts through rates over time as opposed to expensing such costs as incurred.

During the rate-making process for certain of our assets, regulatory authorities set the framework for what we can charge customers for our services and establish the manner that our costs are accounted for, including allowing us to defer recognition of certain costs and permitting recovery of the amounts through rates

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over time as opposed to expensing such costs as incurred.

Certain examples of types of regulatory guidance include costs for fuel and losses, acquisition costs, contributions in aid of construction, charges for depreciation, and gains or losses on disposition of assets.

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A write-off of regulatory assets and costs not recovered may be required if all or a portion of the regulated operations have rates that are no longer (i) established by independent, third-party regulators and (ii) set at levels that will recover our costs when considering the demand and competition for our services.

Retirement and Other Postretirement Employee Benefits - We have a legacy ONEOK defined benefit retirement plan covering certain employees and former employees, as well as two defined benefit pension plans for non-union and union legacy Magellan employees.

We sponsor legacy ONEOK welfare plans that provide postretirement medical and life insurance benefits to certain employees hired prior to 2017 who retire with at least five years of service of full-time consecutive service.

We also sponsor the postretirement benefit obligations, which cover certain legacy Magellan employees.

Retirement and Other Postretirement Employee Benefits - We maintain three defined benefit pension plans, including the ONEOK Retirement Plan, covering certain legacy ONEOK employees, and the Magellan Pension Plan and the Magellan Pension Plan for USW Employees, each covering certain legacy Magellan employees.

We sponsor health and welfare plans that provide postretirement medical and life insurance benefits to certain legacy ONEOK employees hired prior to 2017 and certain legacy Magellan employees who retire after a specified age with at least five years of service and satisfy certain other conditions.

The expense and liability related to these plans is calculated using statistical and other factors that attempt to anticipate future events.

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In determining the projected benefit obligations and costs, assumptions can change from period to period and may result in changes in the costs and liabilities we recognize.

See Note M for our retirement and other postretirement employee benefits disclosures.

See Note L for our retirement and other postretirement employee benefits disclosures.

Income Taxes - Deferred income taxes are provided for the difference between the financial statement and income tax basis of assets and liabilities and carryforward items based on income tax laws and rates existing at the time the temporary differences are expected to reverse.

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We file numerous consolidated and separate income tax returns with federal tax authorities of the United States along with the tax authorities of several states.

EnLink Midstream Operating, LP and EnLink Partners are both under federal audit by the Internal Revenue Service for the calendar years ended Dec.

31, 2019, and Dec.

31, 2020, and statute waivers are in place for these years.

EnLink Midstream Operating, LP and EnLink Partners are both in the process of federal review by the Internal Revenue Service for the calendar years ended December 31, 2019, and December 31, 2020, and statute waivers are in place for these years.

At this time, we believe the audits will close without a material impact.

No other ONEOK entity is under any United States federal audits or statute waivers at this time.

See Note N for our income tax disclosures.

See Note M for our income tax disclosures.

Asset Retirement Obligations - Asset retirement obligations represent legal obligations associated with the retirement of long-lived assets that result from the acquisition, construction, development and/or normal use of the asset.

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For assets in which we are able to make an estimate, the fair value of the liability is added to the carrying amount of the associated asset, and this additional carrying amount is depreciated over the life of the asset.

The liability is accreted at the end of each period through charges to operating expense.

The liability is accreted at the end

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of each period through charges to operating expense.

If the obligation is settled for an amount other than the carrying amount of the liability, we will recognize a gain or loss on settlement.

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Actual results may differ from our estimates resulting in an impact, positive or negative, on earnings.

See Note P for additional discussion of contingencies.

See Note O for additional discussion of contingencies.

Share-Based Payments - We expense the fair value of share-based payments net of estimated forfeitures.

We estimate forfeiture rates based on historical forfeitures under our share-based payment plans.

See Note L for our share-based payments disclosures.

See Note K for our share-based payments disclosures.

Earnings per Common Share - Basic EPS is calculated based on the daily weighted-average number of shares of common stock outstanding during the period, vested restricted and performance units that have been deferred and share awards deferred under the compensation plan for non-employee directors.

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For fiscal-year periods, the dilutive components for each quarter are averaged to arrive at the fiscal year-to-date dilutive component.

See Note K for our EPS disclosures.

See Note J for our EPS disclosures.

Segment Reporting - In accordance with the “Segment Reporting” Topic 280, our chief operating decision-maker has been identified as the chief executive officer, who reviews the financial performance of each of our four segments to make decisions about allocating resources and assessing our financial performance as a whole, on a regular basis.

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Adjusted EBITDA for each segment is defined as net income adjusted for interest expense, depreciation and amortization, noncash impairment charges, income taxes, noncash compensation expense and certain other noncash items.

Following the Magellan Acquisition, we performed a review of our calculation methodology of adjusted EBITDA, and beginning in 2023, we updated our calculation to include adjusted EBITDA related to our unconsolidated affiliates using the same recognition and measurement methods used to record equity in net earnings from investments.

In prior periods, our calculation included equity in net earnings from investments.

This change resulted in an additional $ 62 million of adjusted EBITDA in 2023, and we have not restated prior periods.

Adjusted EBITDA from our unconsolidated affiliates is calculated consistently with the definition above and excludes items such as interest, depreciation, income taxes and other noncash items.

Adjusted EBITDA from our unconsolidated affiliates is calculated consistently with the definition above and excludes items such as interest expense, depreciation and amortization, income taxes and other noncash items.

Although the amounts related to our unconsolidated affiliates are included in the calculation of adjusted EBITDA, such inclusion should not be understood to imply that we have control over the operations and resulting revenues, expenses or cash flows of such unconsolidated affiliates.

This calculation may not be comparable with similarly titled measures of other companies.

See Note S for our segments disclosures.

See Note R for our segments disclosures.

Medford Insurance Proceeds - In 2022, a fire occurred at our 210 MBbl/d Medford, Oklahoma, NGL fractionation facility.

In the first quarter of 2023, we reached an agreement with our insurers to settle all claims for physical damage and business interruption related to the Medford incident.

Under the terms of the settlement agreement, we agreed to resolve the claims for total insurance payments of $ 930 million, $ 100 million of which was received in 2022.

The remaining $ 830 million was received in the first quarter of 2023.

The proceeds serve as settlement for property damage, business interruption claims to the date of the settlement and as payment in lieu of future business interruption insurance claims.

We applied the $ 830 million received to our outstanding insurance receivable at December 31, 2022, of $ 51 million, and recorded an operational gain for the remaining $ 779 million in other operating income, net, within the Consolidated Statement of Income for the year ended December 31, 2023.

We classified proceeds received within the Consolidated Statement of Cash Flows based on our assessment of the nature of the loss (property and business interruption) included in the settlement.

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Recently Issued Accounting Standards Update - Changes to GAAP are established by the FASB in the form of Accounting Standards Update (ASUs) to the FASB Accounting Standards Codification.

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Except as discussed below, there have been no new accounting pronouncements that have become effective or have been issued that are of significance or potential significance to us.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280):

Improvements to Reportable Segment Disclosures , which requires public entities to disclose significant expense categories and amounts for each reportable segment on both an interim and annual basis, consisting of expenses regularly reported to the chief operating decision maker and included in a segment's reported measure of segment profit or loss.

The standard also requires disclosing an amount of other segment items as well as all annual disclosures in interim periods.

ASU 2023-07 is effective for fiscal years beginning after Dec.

15, 2023, and for interim periods within fiscal years beginning after Dec.

15, 2024, with early adoption permitted.

The adoption of this standard did not materially impact us.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740):

Improvements to Income Tax Disclosures , which requires public entities, on an annual basis, to provide disclosure of specific disaggregated information about the reporting entity’s effective tax rate reconciliation as well as information on income taxes paid.

ASU 2023-09 is effective for fiscal years beginning after Dec.

15, 2024, with early adoption permitted.

We do not expect the adoption of this standard to materially impact us.

ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted.

We adopted this standard in 2025 and updated our income tax disclosures retrospectively.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40) , which requires public entities to provide disaggregated information for certain types of costs and expenses included in each income statement caption, such as inventory purchases, employee compensation, depreciation, intangible asset amortization and depletion.

ASU 2024-03 is effective for fiscal years beginning after Dec.

15, 2026, and interim periods beginning after Dec.

15, 2027, with early adoption permitted.

We are currently evaluating the impact of this standard on us.

ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027, with early adoption permitted.

We are currently evaluating the impact of this standard on our disclosures.

In November 2025, the FASB issued ASU 2025-09, Derivatives and Hedging – Hedge Accounting Improvements (Topic 815), which is intended to enhance or clarify Topic 815 to better align hedge accounting with the economics of an entity’s risk management activities, allow hedging of groups of forecasted transactions and expand the types of hedge transactions that can be aggregated.

Additionally, the guidance allows entities to designate a variable price component of a nonfinancial forecasted transaction, facilitate hedge accounting on variable-rate debt and provides clarification related to reference rate reform.

ASU 2025-09 is effective for fiscal years beginning after December 15, 2026, with early adoption permitted.

We elected to adopt this guidance beginning in the first quarter 2026.

The adoption of this standard did not materially impact us.

ACQUISITIONS AND DIVESTITURES

EnLink Controlling Interest Acquisition - On Oct.

15, 2024, we completed the EnLink Controlling Interest Acquisition, acquiring GIP’s interest in EnLink consisting of approximately 43 % of the outstanding EnLink Units for $ 14.90 in cash per unit and 100 % of the outstanding limited liability company interests in the managing member of EnLink for $ 300 million, for total cash consideration of $ 3.3 billion.

BridgeTex Additional Interest Acquisition - On July 22, 2025, we completed the BridgeTex Additional Interest Acquisition.

Pursuant to the purchase agreement, we paid approximately $ 270 million in cash, which we funded with short-term borrowings.

Following the completion of the transaction, we now have a 60 % ownership interest in BridgeTex.

Our investment in BridgeTex will continue to be accounted for using the equity method as we continue to have the ability to exercise significant influence over the operating and financial policies of BridgeTex, although we do not have the ability to exercise control.

Delaware Basin JV Acquisition - On May 28, 2025, we completed the Delaware Basin JV Acquisition for $ 941 million.

Pursuant to the purchase agreement, we paid $ 550 million in cash, including post-closing adjustments, which we funded with short-term borrowings and issued approximately 4.9 million shares of ONEOK common stock to the seller with a fair value of $ 391 million as of the closing date.

Following the completion of the transaction, it is now a wholly owned subsidiary.

As we controlled the Delaware Basin JV at December 31, 2024, prior to the Delaware Basin JV Acquisition, the change in our ownership interest was accounted for as an equity transaction, and no gain or loss was recognized in our Consolidated Statement of Income from the acquisition.

The Delaware Basin JV Acquisition was a taxable exchange.

The transaction resulted in a decrease to the carrying value of noncontrolling interests in consolidated subsidiaries at the acquisition date of $ 678 million and an increase to paid-in capital of $ 185 million, including deferred tax assets.

EnLink Acquisition - On January 31, 2025, we completed the EnLink Acquisition.

Pursuant to the EnLink Merger Agreement, each publicly held common unit of EnLink was exchanged for a fixed ratio of 0.1412 shares of ONEOK common stock, including EnLink Units that were exchanged for all previously outstanding Series B Preferred Units immediately prior to closing.

We issued 41 million shares of common stock with a fair value of $ 4.0 billion.

As a result of the completion of the EnLink Acquisition, common units of EnLink are no longer publicly traded, and EnLink is now a wholly owned subsidiary.

As we controlled EnLink at December 31, 2024, prior to the EnLink Acquisition, the change in our ownership interest was accounted for as an equity transaction.

The carrying value of the noncontrolling interests in consolidated subsidiaries at the acquisition date was $ 4.4 billion.

The difference between the equity consideration and the carrying value of the noncontrolling interests in consolidated subsidiaries at the acquisition date was recognized as an adjustment to paid-in capital.

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Supplemental Cash Flow Information - Our noncash balance sheet activity related to the EnLink Acquisition is as follows (in millions):

Common stock $ 1

Paid-in capital $ 4,377

Noncontrolling interests in consolidated subsidiaries $ ( 4,378 )

EnLink Controlling Interest Acquisition - On October 15, 2024, we completed the EnLink Controlling Interest Acquisition, acquiring GIP’s interest in EnLink consisting of approximately 43 % of the outstanding EnLink Units for $ 14.90 in cash per unit and 100 % of the outstanding limited liability company interests in the managing member of EnLink for $ 300 million, for total cash consideration of $ 3.3 billion.

Through our 100 % ownership of the managing member of EnLink, we obtained control of EnLink.

We used a portion of the proceeds from our September 2024 underwritten public offering of $ 7.0 billion senior unsecured notes to fund this acquisition.

For additional information on our long-term debt, see Note H.

EnLink’s operations are principally composed of providing midstream services relating to natural gas, NGLs and crude oil.

The assets of EnLink include approximately 14,000 miles of pipeline and rights of way, natural gas processing plants with approximately 3.9 Bcf/d of processing capacity, NGL fractionators with approximately 235 MBbl/d of operating capacity, barge and rail terminals, product storage facilities, including natural gas storage, purchasing and marketing capabilities and equity investments in certain joint ventures.

EnLink’s operations are now reported across all four of our existing operating segments, allocated by the nature of the commodities and services provided.

This acquisition meaningfully increases our scale and integrated value chain within the growing Permian Basin while expanding and extending our asset bases in the Mid-Continent, North Texas and Louisiana regions.

We accounted for this acquisition using the acquisition method of accounting for business combinations pursuant to Accounting Standards Codification 805, “Business Combinations,” which requires, among other things, assets acquired and liabilities assumed to be recorded at their fair value on the acquisition date.

Any excess of consideration to be transferred over the estimated fair value of assets acquired and liabilities assumed is recorded as goodwill.

Determining the fair value of acquired assets and liabilities assumed requires management to make estimates, assumptions and judgments, and in some cases, management may also utilize third-party specialists to assist and advise on those estimates.

The purchase price allocation presented below is substantially complete.

However, management continues to refine the preliminary valuation of certain assets acquired and liabilities assumed, such as working capital liabilities and long-lived assets, and may adjust the allocation in subsequent periods.

The final valuation will be completed as we obtain the information necessary to complete the analysis, but no later than one year from the acquisition date.

The following tables set forth the acquisition consideration and preliminary purchase price allocation of assets acquired and liabilities assumed:

For additional information on our long-term debt, see Note G.

This acquisition meaningfully increased our scale and integrated value chain within the growing Permian Basin while expanding and extending our asset bases in the Mid-Continent, North Texas and Louisiana regions.

The EnLink Controlling Interest Acquisition was accounted for using the acquisition method of accounting for business combinations pursuant to Accounting Standards Codification 805, “Business Combinations,” which requires, among other things, assets acquired and liabilities assumed to be recorded at their fair value on the acquisition date.

Determining the fair value of acquired assets and liabilities assumed required management to make estimates, assumptions and judgments, and in some cases, management also utilized third-party specialists to assist and advise on those estimates.

The following tables set forth the acquisition consideration and final purchase price allocation of assets acquired and liabilities assumed:

October 15, 2024

(Millions of dollars and units, except per unit data)

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Total cash consideration $ 3,285

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October 15, 2024

Assets acquired:

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Total purchase price $ 3,285

(a) - Includes obligation to repay Series C Preferred Units.

(a) - Included obligation to repay Series C Preferred Units.

In 2025, there were no material changes to the preliminary purchase price allocation as disclosed in our 2024 Annual Report.

Property, plant and equipment:

Property, plant and equipment consists primarily of pipeline and rights of way, pipeline-related equipment and processing plant and fractionators and will be depreciated on a straight-line basis over the estimated useful lives of the assets.

Property, plant and equipment consisted primarily of pipeline and rights of way, pipeline-related equipment and processing plant and fractionators and will be depreciated on a straight-line basis over the estimated useful lives of the assets.

Intangible assets:

The preliminary value of net identifiable intangible assets relates to customer relationships that will be amortized over the period of expected benefit.

Net identifiable intangible assets related to customer relationships that will be amortized over the period of expected benefit.

Long-term debt, excluding current maturities:

We utilized publicly traded prices to estimate the fair value.

The debt comprises senior unsecured obligations with varying maturities and interest rates as outlined in Note H.

The debt comprised senior unsecured obligations with varying maturities and interest rates as outlined in Note G.

Recognizing the debt at its acquisition date fair value resulted in a discount from the notional value.

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We established deferred income tax liabilities resulting from carryover tax basis, which increased goodwill.

The remainder of the goodwill balance primarily represents commercial synergies.

The remainder of the goodwill balance primarily represented commercial synergies.

Goodwill will not be deductible for tax purposes.

For additional information on goodwill, see Note G.

For additional information on goodwill, see Note F.

Noncontrolling interest:

Represents the approximately 57 % of EnLink Units not acquired in the EnLink Controlling Interest Acquisition, valued at the acquisition date closing price of EnLink, the Series B Preferred Units and partially owned consolidated subsidiaries.

Represented the approximately 57 % of EnLink Units not acquired in the EnLink Controlling Interest Acquisition, valued at the acquisition date closing price of EnLink, the Series B Preferred Units and partially owned consolidated subsidiaries.

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Results of operations:

The results of operations attributable to the EnLink Controlling Interest Acquisition have been included in our Consolidated Financial Statements since the date of acquisition through Dec.

Revenue and income before income taxes attributable to the net assets acquired for the period Oct.

15, 2024, through Dec.

31, 2024, were $ 1.5 billion and $ 173 million, respectively.

Subsequent event - On Jan.

31, 2025, we completed the EnLink Acquisition.

Pursuant to the EnLink Merger Agreement, we acquired all of the EnLink outstanding publicly held common units in a fixed ratio exchange of 0.1412 shares of ONEOK Common stock, including EnLink Units that were exchanged for all previously outstanding Series B Preferred Units immediately prior to closing.

We issued 41 million shares of common stock, with a fair value of $ 4.0 billion.

EnLink is now a wholly owned subsidiary.

As we controlled EnLink prior to the EnLink Acquisition, the change in our ownership interest was accounted for as an equity transaction.

Medallion Acquisition - On Oct.

31, 2024, we completed the Medallion Acquisition with GIP, acquiring all of the equity interests in Medallion for total cash consideration of $ 2.6 billion, inclusive of the purchase of additional interests in a Medallion joint venture owned by a separate third party.

The results of operations attributable to the EnLink Controlling Interest Acquisition have been included in our Consolidated Financial Statements since the date of acquisition.

Revenue and income before income taxes attributable to the net assets acquired for the period October 15, 2024, through December 31, 2024, were $ 1.5 billion and $ 173 million, respectively.

Medallion Acquisition - On October 31, 2024, we completed the Medallion Acquisition with GIP, acquiring all of the equity interests in Medallion for total cash consideration of $ 2.6 billion, inclusive of the purchase of additional interests in a Medallion joint venture owned by a separate third party.

We used a portion of the proceeds from our September 2024 underwritten public offering of $ 7.0 billion senior unsecured notes to fund this acquisition.

For additional information on our long-term debt, see Note H.

This acquisition expands our midstream services for crude oil and condensate in West Texas, specifically the Midland Basin.

The assets of Medallion include crude oil gathering and transportation pipelines and crude oil storage facilities.

For additional information on our long-term debt, see Note G.

This acquisition expanded our midstream services for crude oil and condensate in West Texas, specifically the Midland Basin.

The assets of Medallion included crude oil gathering and transportation pipelines and crude oil storage facilities.

Medallion’s assets and operations are reported in our Refined Products and Crude segment.

Any excess of consideration to be transferred over the estimated fair value of assets acquired and liabilities assumed will be recorded as goodwill.

Determining the fair value of acquired assets and liabilities assumed requires management to make estimates, assumptions and judgments, and in some cases management may also utilize third-party specialists to assist and advise on those estimates.

The purchase price allocation presented below is substantially complete.

The final valuation will be completed as we obtain the information necessary to complete the analysis, but no later than one year from the acquisition date.

The following table sets forth the preliminary purchase price allocation of assets acquired and liabilities assumed:

The Medallion Acquisition was accounted for using the acquisition method of accounting for business combinations pursuant to Accounting Standards Codification 805, “Business Combinations,” which requires, among other things, assets acquired and liabilities assumed to be recorded at their fair value on the acquisition date.

The following table sets forth the final purchase price allocation of assets acquired and liabilities assumed:

October 31, 2024

Assets acquired:

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Accounts receivables, net

Inventories 21

Other current assets 22

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Total purchase price $ 2,617

In 2025, there were no material changes to the preliminary purchase price allocation as disclosed in our 2024 Annual Report.

Property, plant and equipment:

Property, plant and equipment consists primarily of pipeline and pump station equipment and will be depreciated on a straight-line basis over the estimated useful lives of the assets.

Property, plant and equipment consisted primarily of pipeline and pump station equipment and will be depreciated on a straight-line basis over the estimated useful lives of the assets.

Intangible assets:

The preliminary value of net identifiable intangible assets relates to customer relationships that will be amortized over the period of expected benefit.

Goodwill represents commercial synergies, and is expected to be fully deductible for tax purposes.

For additional information on goodwill, see Note G.

Net identifiable intangible assets related to customer relationships that will be amortized over the period of expected benefit.

Goodwill represented commercial synergies and is expected to be fully deductible for tax purposes.

For additional information on goodwill, see Note F.

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Results of operations:

The results of operations attributable to the Medallion Acquisition have been included in our Consolidated Financial Statements since the date of acquisition through Dec.

Revenue and income before income taxes attributable to the net assets acquired for the period Nov.

1, 2024, through Dec.

31, 2024, were $ 256 million and $ 43 million, respectively.

The results of operations attributable to the Medallion Acquisition have been included in our Consolidated Financial Statements since the date of acquisition.

Revenue and income before income taxes attributable to the net assets acquired for the period November 1, 2024, through December 31, 2024, were $ 256 million and $ 43 million, respectively.

Gulf Coast NGL Pipelines Acquisition - On June 17, 2024, we completed the acquisition of a system of NGL pipelines from Easton Energy, a Houston-based midstream company, for approximately $ 280 million.

This acquisition in our Natural Gas Liquids segment includes approximately 450 miles of liquids products pipelines located in the strategic Gulf Coast market centers for NGLs, Refined Products and crude oil.

A portion of the Easton assets are already connected to our Mont Belvieu assets.

We expect to add connections to our Houston-based assets beginning in mid-2025 through the end of 2025.

Interstate Natural Gas Pipeline Divestiture - On Dec.

31, 2024, we sold three of our wholly owned interstate natural gas pipeline systems to DT Midstream, Inc.

for total cash consideration of $ 1.2 billion and recognized a gain of $ 227 million in other operating income, net, within the Consolidated Statement of Income.

This transaction aligns and enhances our capital allocation priorities within our integrated value chain.

These pipeline systems have previously been reported in our Natural Gas Pipelines segment.

Magellan Acquisition - On Sept.

25, 2023, we completed the Magellan Acquisition.

This acquisition strategically diversifies our complementary asset base and allows for significant expected synergies as a combined entity.

This acquisition in our Natural Gas Liquids segment included approximately 450 miles of liquids products pipelines located in the strategic Gulf Coast market centers for NGLs, Refined Products and crude oil.

Interstate Natural Gas Pipeline Divestiture - On December 31, 2024, we sold three of our wholly owned interstate natural gas pipeline systems to DT Midstream, Inc.

for total cash consideration of $ 1.2 billion and recognized a gain of $ 227 million in other operating income, net, within the Consolidated Statement of Income for the year ended December 31, 2024.

This transaction aligned and enhanced our capital allocation priorities within our integrated value chain.

These pipeline systems were previously reported in our Natural Gas Pipelines segment.

Magellan Acquisition - On September 25, 2023, we completed the Magellan Acquisition.

This acquisition strategically diversified our complementary asset base and allows for significant expected synergies as a combined entity.

Each common unit of Magellan was exchanged for a fixed ratio of 0.667 shares of ONEOK common stock and $ 25.00 of cash, for a total consideration of $ 14.1 billion.

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We funded the cash portion of this acquisition with an underwritten public offering of $ 5.25 billion senior unsecured notes.

For additional information on our long-term debt, please see Note H.

For additional information on our long-term debt, please see Note G.

The Magellan Acquisition was accounted for using the acquisition method of accounting for business combinations pursuant to Accounting Standards Codification 805, “Business Combinations,” which requires, among other things, assets acquired and liabilities assumed to be recorded at their fair value on the acquisition date.

Determining the fair value of acquired assets and liabilities assumed requires management’s judgment and the use of independent valuation specialists.

The following tables set forth the acquisition consideration and final purchase price allocation of assets acquired and liabilities assumed:

September 25, 2023

(Millions of dollars and shares/units, except per share/unit data)

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Shares of ONEOK common stock issued

ONEOK common stock closing price on Sept.

25, 2023 $ 66.54

ONEOK common stock closing price on September 25, 2023 $ 66.54

Fair value of common stock issued

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Total consideration

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September 25, 2023

Assets acquired:

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Accounts payable 213

Other current liabilities (a) 721

Other current liabilities 721

Long-term debt, excluding current maturities 4,013

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Total purchase price $ 14,114

(a) - Includes contingent liabilities, primarily related to the amounts accrued for the Corpus Christi matter described in Note P.

In 2024, we recorded adjustments to the preliminary purchase price allocation that resulted in an increase to goodwill of $ 165 million due to additional information received during the measurement period.

The adjustment is due primarily to a decrease in property, plant and equipment of approximately $ 100 million, and an increase to certain contingencies that existed as of the acquisition date.

Property, plant and equipment:

Property, plant and equipment consists primarily of pipeline, pipeline-related equipment, storage tanks and processing equipment and will be depreciated on a straight-line basis over the estimated useful lives of the assets.

Intangible assets:

The preliminary value of net identifiable intangible assets relates to customer relationships that will be amortized over the period of expected benefit.

Long-term debt, excluding current maturities:

We assumed the outstanding debt of Magellan and utilized publicly traded prices to estimate the fair value.

The debt comprises senior unsecured obligations with varying maturities and interest rates as outlined in Note H.

Recognizing the debt at its acquisition date fair value resulted in a discount from the notional value.

The discount will be amortized into interest expense over the remaining life of the debt.

Goodwill primarily represents expected tax benefits from future depreciation and amortization of acquired assets and commercial synergies, and is expected to be fully deductible for tax purposes.

For additional information on goodwill, see Note G.

The preliminary value of net identifiable intangible assets related to customer relationships that will be amortized over the period of expected benefit.

Goodwill primarily represented expected tax benefits from future depreciation and amortization of acquired assets and commercial synergies, and is expected to be fully deductible for tax purposes.

For additional information on goodwill, see Note F.

Transaction Costs - The following table sets forth the impact of acquisition-related transaction costs in our Consolidated Statements of Income as of the periods indicated:

2025 (a) 2024 (b) 2023 (c)

(Millions of dollars)

Transaction costs

$ 81 $ 73 $ 158

Interest expense

(a) - Primarily non-recurring costs related to advisory fees and bridge commitment fees associated with the EnLink Controlling Interest Acquisition and Medallion Acquisition.

(b) - Primarily non-recurring costs related to advisory fees, severance and settlement of share based awards for certain Magellan employees and integrations costs, as well as bridge facility commitment fees associated with the Magellan Acquisition.

$ 81 $ 96 $ 179

(a) - Primarily nonrecurring costs including $ 65 million related primarily to advisory fees and severance and $ 16 million of noncash compensation expense related to the settlement of share-based awards for certain EnLink employees associated with the EnLink Acquisition.

(b) - Primarily nonrecurring costs related to advisory fees and bridge commitment fees associated with the EnLink Controlling Interest Acquisition and Medallion Acquisition.

(c) - Primarily nonrecurring costs related to advisory fees, severance and settlement of share-based awards for certain Magellan employees and integration costs, as well as bridge facility commitment fees associated with the Magellan Acquisition.

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Pro Forma Financial Information (unaudited)

The following table sets forth the unaudited supplemental pro forma financial information for the years ended Dec.

31, 2024, 2023 and 2022, as if we had completed the Magellan Acquisition on Jan.

1, 2022, and the EnLink Controlling Interest Acquisition and the Medallion Acquisition on Jan.

Year Ended Dec.

The following table sets forth the unaudited supplemental pro forma financial information for the years ended December 31, 2024 and 2023, as if we had completed the Magellan Acquisition on January 1, 2022, and the EnLink Controlling Interest Acquisition and the Medallion Acquisition on January 1, 2023:

Year Ended December 31, 2024

EnLink Controlling Interest Acquisition Pro Forma Medallion Acquisition Pro Forma Combined

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Net income $ 3,112 $ 288 $ 81 $ 3,481

Year Ended Dec.

Year Ended December 31, 2023

Pro Forma EnLink Controlling Interest Acquisition Pro Forma Medallion Acquisition Pro Forma Magellan Acquisition Pro Forma Combined

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The summarized unaudited pro forma information reflects the following adjustments:

• Reflects depreciation and amortization based on the preliminary fair values of property, plant and equipment, and intangible assets;

• Reflects non-recurring transaction costs incurred presented above that were reclassified and included in pro forma net income as if they had been incurred as of the earliest period presented for each respective acquisition;

• Reflects depreciation and amortization based on the final fair values of property, plant and equipment, and intangible assets;

• Reflects nonrecurring transaction costs incurred presented above that were reclassified and included in pro forma net income as if they had been incurred as of the earliest period presented for each respective acquisition;

• Reflects interest expense related to the underwritten public offerings of senior unsecured notes used to fund the cash consideration and other costs related to the acquisitions;

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• Reflects the income tax effect of the pro forma adjustments;

• Reflects the elimination of historical activity between ONEOK, EnLink and Medallion.

MEDFORD INCIDENT

In 2022, a fire occurred at our 210 MBbl/d Medford, Oklahoma, NGL fractionation facility.

In the first quarter of 2023, we reached an agreement with our insurers to settle all claims for physical damage and business interruption related to the Medford incident.

Under the terms of the settlement agreement, we agreed to resolve the claims for total insurance payments of $ 930 million, $ 100 million of which was received in 2022.

The remaining $ 830 million was received in the first quarter of 2023.

The proceeds serve as settlement for property damage, business interruption claims to the date of the settlement and as payment in lieu of future business interruption insurance claims.

We applied the $ 830 million received to our outstanding insurance receivable at Dec.

31, 2022, of $ 51 million, and recorded an operational gain for the remaining $ 779 million in other operating income, net, within the Consolidated Statement of Income.

We classified proceeds received within the Consolidated Statement of Cash Flows based on our assessment of the nature of the loss (property and business interruption) included in the settlement.

• Reflects the elimination of historical activity between ONEOK, Magellan, EnLink and Medallion.

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FAIR VALUE MEASUREMENTS

Recurring Fair Value Measurements - The following tables set forth our recurring fair value measurements as of the dates indicated:

December 31, 2025

Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net

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Total derivative liabilities $ ( 21 ) $ ( 46 ) $ — $ ( 67 ) $ 67 $ —

(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheet on a net basis.

(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis.

We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us.

31, 2024, we held no cash and posted cash of $ 45 million with a counterparty, including $ 10 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above.

The remaining $ 35 million of cash collateral in excess of derivative liability positions is included in other current assets in our Consolidated Balance Sheet.

At December 31, 2025, we held no cash and posted cash of $ 4 million with a counterparty, which is included in other current assets in our Consolidated Balance Sheets.

December 31, 2024

Level 1 Level 2 Level 3 Total - Gross Netting (a) Total - Net

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Total derivative liabilities $ ( 40 ) $ ( 46 ) $ — $ ( 86 ) $ 81 $ ( 5 )

(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheet on a net basis.

(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis.

We net derivative assets and liabilities when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us.

31, 2023, we posted no cash and held cash of $ 41 million with various counterparties, which offsets our derivative net asset position under master-netting arrangements as shown in the table above.

At December 31, 2024, we held no cash and posted cash of $ 45 million with a counterparty, including $ 10 million of cash collateral that is offsetting derivative net liability positions under master-netting arrangements in the table above.

The remaining $ 35 million of cash collateral in excess of derivative liability positions is included in other current assets in our Consolidated Balance Sheets.

Other Financial Instruments - The approximate fair value of cash and cash equivalents, accounts receivable, accounts payable and short-term borrowings is equal to book value due to the short-term nature of these items.

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We have investments associated with our supplemental executive retirement plan and nonqualified deferred compensation plan that are carried at fair value and primarily are composed of mutual funds, municipal bonds and other fixed income securities classified as Level 1 and Level 2.

The estimated fair value of our consolidated long-term debt, including current maturities, was $ 30.8 billion and $ 21.4 billion at Dec.

31, 2024 and 2023, respectively.

The book value of our consolidated long-term debt, including current maturities, was $ 32.1 billion and $ 21.7 billion at Dec.

31, 2024 and 2023, respectively.

The book value of our consolidated long-term debt, including current maturities, was $ 32.0 billion and $ 32.1 billion at December 31, 2025 and 2024, respectively.

At December 31, 2025 and 2024, the estimated fair value of our consolidated long-term debt, including current maturities, was $ 32.7 billion and $ 31.9 billion, respectively.

For comparability to the book value of our consolidated long-term debt, the unamortized debt discounts and issuance costs at December 31, 2025 and 2024, totaled $ 1.2 billion and $ 1.1 billion, respectively, which resulted in the estimated fair value, net of unamortized debt discounts and issuance costs, of $ 31.5 billion and $ 30.8 billion, respectively.

The estimated fair value of the aggregate senior notes outstanding was determined using quoted market prices for similar issues with similar terms and maturities.

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Risk-management Activities - We are sensitive to changes in the prices of natural gas, NGLs, Refined Products and crude oil, principally as a result of contractual terms under which these commodities are processed, purchased and sold.

We are also subject to the risk of interest-rate fluctuation in the normal course of business.

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subject to the risk of interest-rate fluctuation in the normal course of business.

We use physical-forward purchases and sales and financial derivatives to secure a certain price for a portion of our natural gas, NGLs, Refined Products, condensate and crude oil purchases and sales;

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To the extent that commodity price risk in our Natural Gas Pipelines segment is not mitigated by fuel cost-recovery mechanisms, we may use physical-forward sales or purchases to reduce the impact of natural gas price fluctuations.

31, 2024 and 2023, there were no financial derivative instruments with respect to our natural gas pipeline operations.

We are also exposed to location price differential risk as a result of the relative value of natural gas purchases at one location and sales at another location, primarily related to our optimization and marketing business.

As part of our hedging strategy, we utilize physical-forward contracts and commodity derivative financial instruments to reduce the impact of price fluctuations related to natural gas.

In our Refined Products and Crude segment, we are primarily exposed to commodity price risk from our liquids blending and marketing activities, as well as product retained during the operations of our pipelines and terminals.

As part of our hedging strategy, we use the previously described commodity derivative financial instruments and physical-forward contracts to reduce the impact of price fluctuations related to NGLs, Refined Products and crude oil.

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Interest-rate risk - We may manage interest-rate risk through the use of fixed-rate debt, floating-rate debt, Treasury locks and interest-rate swaps.

Treasury locks are agreements to pay the difference between the benchmark Treasury rate and the rate that is designated in the terms of the agreement.

In the third quarter of 2024, we entered into $ 1.5 billion of Treasury locks to hedge the variability of interest payments on a portion of our forecasted debt issuances.

In the same quarter, we settled all of our $ 1.5 billion Treasury locks related to our underwritten public offering of $ 7.0 billion senior unsecured notes associated with the EnLink Controlling Interest Acquisition and Medallion Acquisition.

In the third quarter and second quarter of 2025, we entered into $ 300 million notional quantity and $ 700 million notional quantity, respectively, of Treasury locks to hedge the variability of interest payments on a portion of our forecasted debt issuances.

In the third quarter of 2025, we settled all of the outstanding $ 1.0 billion notional quantity of Treasury locks in connection with our underwritten public offering of $ 3.0 billion senior unsecured notes in August 2025.

All of our Treasury locks were designated as cash flow hedges.

31, 2024, and Dec.

31, 2023, we h ad no outsta nding Treasury lock agreements.

Interest-rate swaps are agreements to exchange interest payments at some future point based on specified notional amounts.

EnLink previously entered into $ 400 million interest rate swaps associated with the EnLink Revolving Credit Facility and the EnLink AR Facility.

In December 2024, EnLink terminated the $ 400 million interest rate swaps upon repayment of outstanding amounts under the EnLink Revolving Credit Facility and the termination of the EnLink AR Facility.

31, 2024, and Dec.

31, 2023, we h ad no outsta nding interest-rate swap agreements.

At December 31, 2025, and December 31, 2024, we had no outstanding interest-rate derivative instruments.

Fair Values of Derivative Instruments - See Note A for a discussion of the inputs associated with our fair value measurements.

The following table sets forth the fair values of our derivative instruments presented on a gross basis as of the dates indicated:

31, 2024 Dec.

December 31, 2025 December 31, 2024

Location in our Consolidated Balance Sheets Assets (Liabilities) Assets (Liabilities)

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Commodity contracts (a)(b) Other current assets/liabilities 17 ( 17 ) 36 ( 33 )

36 ( 33 ) 14 ( 6 )

Other deferred credits — — — ( 6 )

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(a) - Derivative assets and liabilities are presented in our Consolidated Balance Sheets on a net basis when a legally enforceable master-netting arrangement exists between the counterparty to a derivative contract and us.

(b) - At Dec.

31, 2024, our derivative net liability positions under master-netting arrangements for financial commodity contracts were offset by cash collateral of $ 10 million.

Notional Quantities for Derivative Instruments - The following table sets forth the notional quantities for derivative instruments held as of the dates indicated:

Type Net Purchased/Payor (Sold/Receiver)

(b) - At December 31, 2024, our derivative net liability positions under master-netting arrangements for financial commodity contracts were offset by cash collateral of $ 10 million.

Notional Quantities for Derivative Instruments - The following table sets forth the notional quantities for our derivative instruments, consisting of futures and swaps, held as of the dates indicated:

December 31, 2025 December 31, 2024

Net Purchased/Payor

(Sold/Receiver)

Derivatives designated as hedging instruments:

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- Natural gas ( Bcf )

Futures and swaps ( 12.2 ) ( 16.0 )

( 19.4 ) ( 12.2 )

- NGLs, Refined Products and crude oil (MMBbl)

Futures and swaps ( 12.2 ) ( 14.5 )

-Power (Gigawatt hour)

Futures and swaps — 22.1

( 22.1 ) ( 12.2 )

- Natural gas ( Bcf )

Futures and swaps ( 11.2 ) ( 16.0 )

( 17.9 ) ( 11.2 )

- NGLs, Refined Products and crude oil (MMBbl)

Derivatives not designated as hedging instruments:

- Natural gas ( Bcf )

Futures and swaps ( 8.0 ) ( 0.7 )

( 4.1 ) ( 8.0 )

- NGLs, Refined Products and crude oil (MMBbl)

Futures and swaps ( 2.7 ) 0.1

- Natural gas ( Bcf )

Futures and swaps ( 3.7 ) ( 0.7 )

( 0.2 ) ( 3.7 )

- NGLs, Refined Products and crude oil (MMBbl)

Futures and swaps ( 0.2 ) ( 0.1 )

- Natural gas ( Bcf )

Futures and swaps ( 0.2 ) —

Cash Flow Hedges - At Dec.

31, 2024 and 2023, the accumulated other comprehensive income (loss) relating to risk-management assets and liabilities, net of taxes, was $( 38 ) million and $ 31 million, respectively.

Corresponding unrealized gains (losses) related to risk-management assets and liabilities at Dec.

31, 2024, are not material.

( 0.6 ) ( 0.2 )

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Cash Flow Hedges - At December 31, 2025 and 2024, the accumulated other comprehensive income (loss) relating to risk-management assets and liabilities, net of taxes, was $ 19 million and $( 38 ) million, respectively.

Corresponding unrealized gains (losses) related to risk-management assets and liabilities at December 31, 2025 and 2024, are not material.

The following table sets forth the unrealized change in fair value of cash flow hedges in other comprehensive income (loss) for the periods indicated:

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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Accumulated Other Comprehensive Loss into

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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We maintain credit policies with regard to our counterparties that we believe minimize credit risk.

standardized master-netting agreements that allow us to net the positive and negative exposures associated with a single counterparty.

These policies include an evaluation of potential counterparties’ financial condition (including credit ratings, bond yields and credit default swap rates), collateral requirements under certain circumstances and the use of standardized master-netting agreements that allow us to net the positive and negative exposures associated with a single counterparty.

We use internally developed credit ratings for counterparties that do not have a credit rating.

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Based on our policies, exposures, credit and other reserves, we do not anticipate a material adverse effect on our financial position or results of operations as a result of counterparty nonperformance.

31, 2024, the credit exposure from our derivative assets is with investment-grade companies in the financial services sector.

At December 31, 2025, the credit exposure from our derivative assets is with investment-grade companies in the financial services sector.

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PROPERTY, PLANT AND EQUIPMENT

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Estimated Useful

Lives (Years) Dec.

Lives (Years) December 31,

2025 December 31,

(Millions of dollars )

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Processing and fractionation and related equipment 3 to 40

12,594 12,406

Storage and related equipment 5 to 54

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Net property, plant and equipment $ 47,861 $ 45,935

The depreciation expense for the years ended Dec.

31, 2024 and 2023, was $ 1.1 billion and $ 736 million, respectively.

We incurred costs for construction work in process that had not been paid at Dec.

31, 2024, 2023 and 2022, of $ 179 million, $ 242 million and $ 171 million, respectively.

The depreciation expense for the years ended December 31, 2025, 2024 and 2023 was $ 1.4 billion, $ 1.1 billion and $ 736 million, respectively.

We incurred costs for construction work in process that had not been paid at December 31, 2025, 2024 and 2023, of $ 173 million, $ 179 million and $ 242 million, respectively.

Such amounts are not included in capital expenditures (less AFUDC) on the Consolidated Statements of Cash Flows.

EnLink Controlling Interest Acquisition - In October 2024, we completed the EnLink Controlling Interest Acquisition and acquired property, plant and equipment, which primarily include pipeline and rights of way, pipeline-related equipment, processing plant and fractionators valued at $ 11.4 billion.

Medallion Acquisition - In October 2024, we completed the Medallion Acquisition and acquired property, plant and equipment, which primarily include pipeline and pump station equipment, valued at $ 1.6 billion.

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These assets, which are primarily transmission pipelines and related equipment, had a gross cost basis of $ 1.3 billion.

Magellan Acquisition - In September 2023, we completed the Magellan Acquisition and acquired property, plant and equipment, which primarily include pipeline, pipeline-related equipment, storage tanks and processing equipment, valued at $ 11.6 billion.

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GOODWILL AND INTANGIBLE ASSETS

Goodwill - The following table sets forth our goodwill, by segment, for the period indicated:

Goodwill - The following table sets forth our goodwill, by segment, for the periods indicated:

Gathering and

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Liquids Natural Gas

Pipelines Refined Products and Crude

Pipelines Refined Products and Crude Total

( Millions of dollars )

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Accumulated impairment losses ( 153 ) — — — ( 153 )

31, 2023 — 371 157 4,424 4,952

Magellan Acquisition measurement period adjustments (a) — — — 165 165

EnLink Controlling Interest Acquisition (b) 486 1,461 229 541 2,717

Medallion Acquisition (c)

— — — 259 259

Gulf Coast NGL pipeline acquisition

Interstate natural gas pipeline divestiture

— — ( 33 ) — ( 33 )

31, 2024 $ 486 $ 1,863 $ 353 $ 5,389 $ 8,091

(a) - During the remaining measurement period subsequent to Dec.

31, 2023, we recorded adjustments to the Magellan preliminary purchase price allocation that resulted in an increase to goodwill of $ 165 million.

(b) - We established deferred income tax liabilities resulting from the carryover tax basis, which increased goodwill.

The remainder of the goodwill primarily represents commercial synergies.

Goodwill will not be deductible for tax purposes.

The allocation of goodwill is preliminary and may be updated as we continue to evaluate the benefits of expected commercial synergies to our segments.

December 31, 2024 486 1,863 353 5,389 8,091

EnLink Controlling Interest Acquisition adjustment 8 ( 45 ) 2 ( 2 ) ( 37 )

Medallion Acquisition adjustment — — — 4 4

December 31, 2025 $ 494 $ 1,818 $ 355 $ 5,391 $ 8,058

Intangible Assets - Our intangible assets relate primarily to acquired customer relationships from our recent acquisitions and are being amortized on a straight-line basis over a weighted average life of 26 years.

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(Millions of dollars)

Gross intangible assets (a) $ 3,290 $ 1,505

Gross intangible assets $ 3,290 $ 3,290

Accumulated amortization ( 389 ) ( 251 )

Intangible assets, net $ 2,901 $ 3,039

$ 3,039 $ 1,316

(a) - Increases to gross intangible assets primarily represent customer relationships associated with the EnLink Controlling Interest Acquisition and the Medallion Acquisition.

The following table sets forth ONEOK and ONEOK Partners debt as of the dates indicated:

31, 2024 Dec.

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The following table sets forth our consolidated debt as of the dates indicated:

December 31, 2025 December 31, 2024

(Millions of dollars)

Commercial paper outstanding (a) $ — $ —

Commercial paper outstanding, bearing a weighted-average interest rate of 3.91 % as of December 31, 2025 (a)

Senior unsecured obligations:

$ 500 at 2.75 % due September 2024

$ 250 at 3.2 % due March 2025

$ 750 at 4.15 % due June 2025 (b)

$ 400 at 2.2 % due September 2025

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$ 650 at 5.0 % due March 2026

$ 500 at 4.85 % due July 2026 (b)

$ 750 at 5.55 % due November 2026

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$ 1,250 at 4.25 % due September 2027

$ 500 at 5.625 % due January 2028 (b)

$ 800 at 4.55 % due July 2028

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$ 700 at 4.35 % due March 2029

$ 500 at 5.375 % due June 2029 (b)

$ 750 at 3.4 % due September 2029

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$ 500 at 3.25 % due June 2030

$ 1,000 at 6.5 % due September 2030 (b)

$ 500 at 5.8 % due November 2030

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$ 1,250 at 4.75 % due October 2031

$ 750 at 4.95 % due October 2032

$ 750 at 6.1 % due November 2032

$ 1,500 at 6.05 % due September 2033

$ 500 at 5.65 % due September 2034 (b)

$ 1,600 at 5.05 % due November 2034

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$ 1,000 at 5.4 % due October 2035

$ 600 at 6.65 % due October 2036

$ 250 at 6.4 % due May 2037

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$ 550 at 5.15 % due October 2043

$ 350 at 5.6 % due April 2044 (b)

$ 250 at 4.2 % due March 2045

$ 450 at 5.05 % due April 2045 (b)

$ 500 at 4.25 % due September 2046

$ 500 at 5.45 % due June 2047 (b)

$ 700 at 4.95 % due July 2047

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$ 1,500 at 5.7 % due November 2054

$ 1,250 at 6.25 % due October 2055

$ 800 at 5.85 % due November 2064

Guardian $ 120 term loan, rate of 6.58 % as of Dec.

Viking $ 60 term loan, rate of 6.71 % as of Dec.

Total ONEOK and ONEOK Partners debt

28,630 22,794

Total debt 33,965 33,243

Unamortized debt discounts ( 979 ) ( 1,000 )

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Current maturities of long-term debt ( 1,241 ) ( 1,059 )

Long-term ONEOK and ONEOK Partners debt

$ 26,835 $ 21,183

Short-term borrowings (a) ( 820 ) —

Long-term debt $ 30,755 $ 31,018

(a) - Individual issuances of commercial paper under our commercial paper program generally mature in 90 days or less.

(b) - In December 2024, we repaid the Guardian $ 120 million and the Viking $ 60 million term loan agreements, plus accrued and unpaid interest, with cash on hand, as part of the interstate natural gas pipeline divestiture.

The following table sets forth EnLink and EnLink Partners’ debt, which was acquired in the EnLink Controlling Interest Acquisition on Oct.

(Millions of dollars)

Senior unsecured obligations:

$ 750 at 4.15 % due June 2025

$ 500 at 4.85 % due July 2026

$ 500 at 5.625 % due January 2028

$ 500 at 5.375 % due June 2029

$ 1,000 at 6.5 % due September 2030

$ 500 at 5.65 % due September 2034

$ 350 at 5.6 % due April 2044

$ 450 at 5.05 % due April 2045

$ 500 at 5.45 % due June 2047

Total EnLink debt

Unamortized debt discounts, net

Current maturities of long-term debt

Long-term EnLink debt

(a) - Amounts are presented at face value with discount to fair value included in unamortized debt discounts, net.

Debt Guarantees - ONEOK, ONEOK Partners, the Intermediate Partnership and Magellan (Obligated Group) have cross guarantees in place for ONEOK’s and ONEOK Partners’ indebtedness.

31, 2024, EnLink was a subsidiary of ONEOK, did not guarantee ONEOK or ONEOK Partners’ indebtedness and was excluded from the Obligated Group.

EnLink and EnLink Partners’ outstanding debt securities presented in the table above were not guaranteed by the Obligated Group as of Dec.

Subsequent event - At the completion of the EnLink Acquisition on Jan.

31, 2025, ONEOK assumed the outstanding debt of EnLink and EnLink Partners (the Assumed Debt) such that EnLink and EnLink Partners were each released from all debt obligations and provided a guarantee for our and ONEOK Partners’ indebtedness to the holders of each series of outstanding securities, including for the Assumed Debt.

EnLink and EnLink Partners are now included in the Obligated Group.

$ 2.5 Billion Credit Agreement - Our $ 2.5 Billion Credit Agreement is a revolving credit facility and contains certain customary conditions for borrowing, as well as customary financial, affirmative and negative covenants.

Among other things, these covenants include maintaining a ratio of consolidated net indebtedness to adjusted EBITDA (EBITDA, as defined in our $ 2.5 Billion Credit Agreement, adjusted for all noncash charges and increased for projected EBITDA from certain lender-approved capital expansion projects).

In addition, adjusted EBITDA as defined in our $ 2.5 Billion Credit Agreement allows inclusion of the trailing 12 months of consolidated adjusted EBITDA of the acquired business.

In May 2024, we entered into an amendment to our $ 2.5 Billion Credit Agreement that extended the maturity date by one year , from June 2027 to June 2028.

All other terms and conditions of our $ 2.5 Billion Credit Agreement remain unchanged.

In June 2024, we completed the acquisition of a system of NGL pipelines, which allowed us to elect an acquisition adjustment period under our $ 2.5 Billion Credit Agreement and, as a result, increased our leverage ratio covenant to 5.5 to 1.

In October 2024, we completed the EnLink Controlling Interest Acquisition and Medallion Acquisition, which effectively extended our acquisition adjustment period until the quarter ending June 30, 2025, after which it will decrease to 5.0 to 1.

(b) - As of December 31, 2024, amounts represent EnLink and EnLink Partners’ debt acquired in the EnLink Controlling Interest Acquisition on October 15, 2024.

At the completion of the EnLink Acquisition on January 31, 2025, ONEOK assumed the outstanding debt of EnLink and EnLink Partners.

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Commercial Paper Program - In September 2025, we increased the size of our commercial paper program to $ 3.5 billion from $ 2.5 billion.

$ 3.5 Billion Credit Agreement - In February 2025, we amended and restated our $ 2.5 Billion Credit Agreement to increase the size to $ 3.5 billion, extend the term to February 2030 and make other nonmaterial modifications.

Our $ 3.5 Billion Credit Agreement is a revolving credit facility and contains certain customary conditions for borrowing, as well as customary financial, affirmative and negative covenants.

Among other things, these covenants include maintaining a ratio of consolidated net indebtedness to adjusted EBITDA (EBITDA, as defined in our $ 3.5 Billion Credit Agreement, adjusted for all noncash items and increased for projected EBITDA from certain lender-approved capital expansion projects).

In addition, adjusted EBITDA as defined in our $ 3.5 Billion Credit Agreement allows inclusion of the trailing 12 months of consolidated adjusted EBITDA of an acquired business.

In December 2025, we completed the acquisition of a system of gas gathering assets, which allowed us to effectively extend the acquisition adjustment period under our $ 3.5 Billion Credit Agreement and, as a result, our leverage ratio covenant of 5.5 to 1 was extended through the quarter ending June 30, 2026, after which it will decrease to 5.0 to 1.

The $ 3.5 Billion Credit Agreement includes a $ 100 million sublimit for the issuance of standby letters of credit and a $ 200 million sublimit for swingline loans.

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Under our current credit ratings, the applicable rate is 15 basis points.

We have the option to request an additional one-year maturity extension, subject to lender approvals.

We have the option to request two additional one-year maturity extensions, subject to lender approvals.

The $ 3.5 Billion Credit Agreement also contains various customary events of default, the occurrence of which could result in a termination of the lenders’ commitments and the acceleration of all of our obligations thereunder.

2024, we had no outstanding borrowings, our ratio of consolidated indebtedness to adjusted EBITDA was 4.0 to 1, and we were in compliance with all covenants under our $ 2.5 Billion Credit Agreement.

Subsequent event - In February 2025, we amended and restated our $ 2.5 Billion Credit Agreement to increase the size to $ 3.5 billion, extend the term to February 2030 and make other non-material modifications.

All other terms and conditions are substantially the same.

EnLink Revolving Credit Facility - In October 2024, we completed the EnLink Controlling Interest Acquisition and as a result, we acquired the EnLink Revolving Credit Facility.

The EnLink Revolving Credit Facility, which matures in June 2027, is a $ 1.4 billion unsecured revolving credit facility which includes a $ 500 million letter of credit subfacility.

Borrowings under the EnLink Revolving Credit Facility bear interest at Term SOFR plus a Term SOFR spread adjustment of 0.10 % per annum and an applicable margin (ranging from 1.125 % to 2.00 %) or the Base Rate (the highest of the federal funds rate plus 0.50 %, one-month Adjusted Term SOFR plus 1.0 % or the administrative agent’s prime rate) plus an applicable margin (ranging from 0.125 % to 1.00 %).

The EnLink Revolving Credit Facility contains certain financial, operational and legal covenants.

31, 2024, we had no borrowings outstanding and we were in compliance with the financial covenants of the EnLink Revolving Credit Facility.

Subsequent event - Upon closing of the EnLink Acquisition on Jan.

31, 2025, the EnLink Revolving Credit Facility was terminated.

EnLink AR Facility - In October 2024, we completed the EnLink Controlling Interest Acquisition and as a result, we acquired the $ 500 million EnLink AR Facility.

In December 2024, EnLink terminated the AR Facility, and we entered into an agreement to provide revolving unsecured loans to EnLink through a promissory note at an interest rate of 4.85 % at Dec.

This is a floating rate agreement, which bears interest at ONEOK’s current short-term borrowing rate plus 0.25 %.

31, 2024, we held a promissory note receivable of $ 510 million, which was eliminated in consolidation.

As of December 31, 2025, we had no outstanding borrowings, our ratio of consolidated indebtedness to adjusted EBITDA was 4.3 to 1, and we were in compliance with all covenants under our $ 3.5 Billion Credit Agreement.

EnLink Acquisitions - In October 2024, we completed the EnLink Controlling Interest Acquisition and, as a result, we acquired the EnLink Revolving Credit Facility.

The EnLink Revolving Credit Facility, which would have matured in June 2027, was a $ 1.4 billion unsecured revolving credit facility that included a $ 500 million letter of credit subfacility.

Borrowings under the EnLink Revolving Credit Facility bore interest at Term SOFR plus a Term SOFR spread adjustment of 0.10 % per annum and an applicable margin (ranging from 1.125 % to 2.00 %) or the Base Rate (the highest of the federal funds rate plus 0.50 %, one-month Adjusted Term SOFR plus 1.0 % or the administrative agent’s prime rate) plus an applicable margin (ranging from 0.125 % to 1.00 %).

Upon closing of the EnLink Acquisition on January 31, 2025, the EnLink Revolving Credit Facility was terminated.

In October 2024, we completed the EnLink Controlling Interest Acquisition and, as a result, we acquired the $ 500 million EnLink AR Facility.

In December 2024, EnLink terminated the EnLink AR Facility, and we entered into an agreement to provide revolving unsecured loans to EnLink through a promissory note at an interest rate of 4.85 % at December 31, 2024.

This was a floating rate agreement, which bore interest at ONEOK’s current short-term borrowing rate plus 0.25 %.

At December 31, 2024, we held a promissory note receivable of $ 510 million, which was eliminated in consolidation.

Interest earned from this agreement was not material.

Subsequent Event - Upon closing of the EnLink Acquisition on Jan.

31, 2025, we effectively terminated the agreement to provide revolving unsecured loans to EnLink.

Upon closing of the EnLink Acquisition on January 31, 2025, we terminated the agreement to provide revolving unsecured loans to EnLink through a promissory note.

Senior Unsecured Obligations - All notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness, and are structurally subordinate to any of the existing and future debt and other liabilities of any nonguarantor subsidiaries.

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Debt Issuances - We completed the following underwritten public offerings for the periods presented:

Interest Coupon Interest

(Millions of dollars) (Millions of dollars) (Millions of dollars)

$ 1,250 4.25 % $ 750 5.55 %

600 4.4 % 750 5.65 %

1,250 4.75 % 500 5.80 %

1,600 5.05 % 1,500 6.05 % $ 750 6.1 %

1,500 5.7 % 1,750 6.625 %

$ 7,000 $ 5,250 $ 750

2025 (a) 2024 (b) 2023 (c)

Principal Interest Principal Interest Principal Interest

(Millions of dollars, except for percentages)

3 year note $ 1,250 4.25 % $ 750 5.55 %

5 year note 600 4.4 % 750 5.65 %

7 year note $ 750 4.95 % 1,250 4.75 % 500 5.80 %

10 year note 1,000 5.4 % 1,600 5.05 % 1,500 6.05 %

30 year note 1,250 6.25 % 1,500 5.7 % 1,750 6.625 %

40 year note 800 5.85 %

Total $ 3,000 $ 7,000 $ 5,250

(a) - The net proceeds, after deducting underwriting discounts, commissions and offering expenses, were $ 2.96 billion.

The net proceeds from this offering were used to fund the EnLink Controlling Interest Acquisition and the Medallion Acquisition, purchase additional interests in a Medallion joint venture owned by a separate third party, to pay fees and expenses related to the acquisitions and to repay outstanding indebtedness.

The net proceeds from this offering were partially used to repay our commercial paper outstanding and repay in full at maturity our senior notes due September 2025.

The remaining net proceeds from the offering were used for general corporate purposes, including the repurchase and redemption of existing notes.

(b) - The net proceeds, after deducting underwriting discounts, commissions and offering expenses, were $ 6.9 billion.

The net proceeds were used to fund the cash consideration and other costs related to the Magellan Acquisition.

The remainder was used for general corporate purposes.

Debt Repayments - In December 2024, we redeemed our $ 500 million, 4.9 % senior notes due March 2025 at 100 % of the principal amount, plus accrued and unpaid interest, with cash on hand.

In December 2024, we repaid $ 120 million of borrowings under the Guardian Term Loan Agreement and $ 60 million of borrowings under the Viking Term Loan Agreement, plus accrued and unpaid interest, with cash on hand, as part of the interstate natural gas pipeline divestiture.

Subsequent to the EnLink Controlling Interest Acquisition, we repaid $ 465 million of borrowings under the EnLink Revolving Credit Facility with cash on hand.

Subsequent to the EnLink Controlling Interest Acquisition, we repaid $ 374 million of borrowings under the EnLink AR Facility with cash on hand and terminated the EnLink AR Facility.

In September 2024, we repaid the remaining $ 484 million of our $ 500 million, 2.75 % senior notes at maturity with cash on hand.

In 2023, we repurchased in the open market outstanding principal of certain of our senior notes in the amount of $ 322 million for an aggregate repurchase price of $ 280 million, including accrued and unpaid interest, with cash on hand.

In connection with these open market repurchases, we recognized $ 41 million of net gains on extinguishment of debt, which is included in other income (expense), net in our Consolidated Statement of Income for the year ended Dec.

In 2023, we redeemed our $ 500 million, 7.5 % senior notes due September 2023 at 100 % of the principal amount, plus accrued and unpaid interest, with cash on hand.

In 2023, we redeemed our $ 425 million, 5.0 % senior notes due September 2023 at 100 % of the principal amount, plus accrued and unpaid interest, with cash on hand.

In 2022, we redeemed the remaining $ 896 million of our 3.375 % senior notes due October 2022 at 100 % of the principal amount, plus accrued and unpaid interest, with cash on hand and short-term borrowings.

The aggregate maturities of long-term debt outstanding and interest payments on total debt outstanding as of Dec.

31, 2024, for the years 2025 through 2029 are shown below:

Debt Extinguishments - We completed the following debt extinguishments for the periods presented:

2025 2024 2023

Principal Principal Principal

(Millions of dollars, except for percentages)

$ 250 at 3.2 % due March 2025

$ 250 $ 500 at 2.75 % due September 2024

$ 484 $ 500 at 7.5 % due September 2023 (a)

$ 750 at 4.15 % due June 2025

422 $ 500 at 4.9 % due March 2025 (a)

500 $ 425 at 5.0 % due September 2023 (a)

$ 400 at 2.2 % due September 2025

387 Guardian Term Loan Agreement 120 Open Market Repurchases (c) 322

$ 600 at 5.85 % due January 2026 (a)

600 Viking Term Loan Agreement 60

$ 650 at 5.0 % due March 2026 (a)

650 EnLink Revolving Credit Facility 465

Open Market Repurchases (b)

789 EnLink AR Facility 374

$ 3,098 $ 2,003 $ 1,247

(a) - Amounts redeemed at 100% of principal plus accrued and unpaid interest.

(b) - In 2025, we repurchased in the open market certain of our senior notes in the principal amount of $ 789 million for an aggregate repurchase price of $ 681 million, including accrued and unpaid interest.

In connection with these open market repurchases, we recognized $ 106 million of net gains on extinguishment of debt which is included in other income, net in our Consolidated Statement of Income for the year ended December 31, 2025.

(c) - In 2023, we repurchased in the open market certain of our senior notes in the principal amount of $ 322 million for an aggregate repurchase price of $ 280 million, including accrued and unpaid interest.

In connection with these open market repurchases, we recognized $ 41 million of net gains on extinguishment of debt which is included in other income, net in our Consolidated Statement of Income for the year ended December 31, 2023.

The aggregate maturities of long-term debt outstanding and interest payments on total debt outstanding as of December 31, 2025, for the years 2026 through 2030 are shown below:

Obligations Interest

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2030 $ 2,780 $ 1,341 $ 4,121

Compliance with Debt Covenants - As of Dec.

31, 2024, we were in compliance with the covenants contained in our various debt agreements.

Compliance with Debt Covenants - As of December 31, 2025, we were in compliance with the covenants contained in our various debt agreements.

Other - We amortize premiums, discounts and expenses incurred in connection with the issuance of long-term debt consistent with the terms of the respective debt instrument.

Noncontrolling Interests - In October 2024, we completed the EnLink Controlling Interest Acquisition, acquiring GIP’s interest in EnLink consisting of approximately 43 % of the outstanding EnLink Units.

In connection with the EnLink Controlling Interest Acquisition, we recorded noncontrolling interest with a fair value of $ 5.1 billion representing the approximately 57 % of outstanding EnLink Units we did not own, the Series B Preferred Units and partially owned consolidated subsidiaries of EnLink.

Included within noncontrolling interest are Series B Preferred Units, which were issued under EnLink Partners’ partnership agreement and represent noncontrolling ownership interests in EnLink Partners.

EnLink Partners is a controlled subsidiary of EnLink in which EnLink owns all of the outstanding common units.

Series B Preferred Units are exchangeable for EnLink Units in an amount equal to the number of outstanding Series B Preferred Units multiplied by an exchange ratio of 1.15 , subject to certain adjustments.

The exchange is subject to our option to pay cash instead of issuing additional EnLink common units.

31, 2024, $ 515 million of noncontrolling interest on our Consolidated Balance Sheet relate to Series B Preferred Units, and there were 27.4 million units outstanding.

There were no Series B Preferred Units converted or redeemed during the ownership period of Oct.

15, 2024 through Dec.

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Debt Guarantees - At the completion of the EnLink Acquisition on January 31, 2025, ONEOK assumed the outstanding debt of EnLink and EnLink Partners (the “Assumed Debt”).

EnLink and EnLink Partners were released as primary obligors from all debt obligations under the Assumed Debt, but each entity provided a guarantee for our and ONEOK Partners’ indebtedness to the holders of each series of outstanding securities, including for the Assumed Debt.

ONEOK, ONEOK Partners, the Intermediate Partnership, Magellan, EnLink and EnLink Partners have cross guarantees in place for ONEOK’s and ONEOK Partners’ indebtedness.

Noncontrolling Interests - As of December 31, 2025, noncontrolling interests in our Consolidated Balance Sheets related to Ascension and MBTC Pipeline.

On February 4, 2025, we announced a definitive agreement to form the MBTC Pipeline joint venture, of which we own 80 %.

In October 2024, we completed the EnLink Controlling Interest Acquisition, acquiring GIP’s interest in EnLink consisting of approximately 43 % of the outstanding EnLink Units.

In connection with the EnLink Controlling Interest Acquisition, we recorded noncontrolling interests with a fair value of $ 5.1 billion representing the approximately 57 % of outstanding EnLink Units we did not own, the Series B Preferred Units and partially owned consolidated subsidiaries of EnLink.

As of December 31, 2024, included within noncontrolling interests are Series B Preferred Units, which were issued under EnLink Partners’ partnership agreement and represent noncontrolling ownership interests in EnLink Partners.

EnLink Partners was a controlled subsidiary of EnLink in which EnLink owned all of the outstanding common units.

Series B Preferred Units were exchangeable for EnLink Units in an amount equal to the number of outstanding Series B Preferred Units multiplied by an exchange ratio of 1.15 , subject to certain adjustments.

The exchange was subject to our option to pay cash instead of issuing additional EnLink common units.

As of December 31, 2024, $ 515 million of noncontrolling interest on our Consolidated Balance Sheets related to Series B Preferred Units, and there were 27.4 million units outstanding.

There were no Series B Preferred Units converted or redeemed during the ownership period of October 15, 2024, through December 31, 2024.

Distributions made on Series B Preferred Units were not material.

EnLink owns a 50.1 % interest in the Delaware Basin JV, which owns processing facilities located in the Delaware Basin in Texas.

Noncontrolling interest includes the other owner’s minority interest in the Delaware Basin JV.

31, 2024, $ 684 million of noncontrolling interest on our Consolidated Balance Sheet relates to the Delaware Basin JV.

The other partially owned consolidated subsidiary of EnLink is not material.

Subsequent event - On Jan.

31, 2025, we completed the EnLink Acquisition.

Pursuant to the EnLink Merger Agreement, each common unit of EnLink was exchanged for a fixed ratio of 0.1412 shares of ONEOK Common stock, including EnLink Units that were exchanged for all previously outstanding Series B Preferred Units immediately prior to closing.

We issued 41 million shares of common stock, with a fair value of $ 4.0 billion.

There are no remaining Series B Preferred Units outstanding.

As of December 31, 2024, EnLink owned a 50.1 % interest in the Delaware Basin JV, which owns processing facilities located in the Delaware Basin in Texas.

Noncontrolling interests included the other owner’s minority interest in the Delaware Basin JV.

As of December 31, 2024, $ 684 million of noncontrolling interests on our Consolidated Balance Sheets related to the Delaware Basin JV and the other partially owned consolidated subsidiary of EnLink was not material.

Series A and B Convertible Preferred Stock - There are no shares of Series A or Series B Preferred Stock currently issued or outstanding.

EnLink Series C Preferred Units - Series C Preferred Units represented noncontrolling ownership interests in EnLink Partners.

In September 2024, EnLink gave notice to redeem all of its outstanding Series C Preferred Units, and reclassified the obligation to a liability on their Consolidated Balance Sheet.

17, 2024, EnLink redeemed all outstanding Series C Preferred Units at $ 1,000 per Series C Preferred Unit, plus $ 8.28 per Series C Preferred Unit of unpaid distributions, for $ 365 million with proceeds received from borrowings under the EnLink Revolving Credit Facility.

2024, there are no remaining Series C Preferred Units outstanding.

Equity Issuances - In September 2023, we completed the Magellan Acquisition.

Pursuant to the Merger Agreement, each common unit of Magellan was exchanged for a fixed ratio of 0.667 shares of ONEOK common stock and $ 25.00 of cash.

We issued approximately 135 million shares of common stock, with a fair value of approximately $ 9.0 billion as of the closing date of the Magellan Acquisition.

In September 2024, EnLink gave notice to redeem all of its outstanding Series C Preferred Units, and reclassified the obligation to a liability on their Consolidated Balance Sheets.

On October 17, 2024, EnLink redeemed all outstanding Series C Preferred Units at $ 1,000 per Series C Preferred Unit, plus $ 8.28 per Series C Preferred Unit of unpaid distributions, for $ 365 million with proceeds received from borrowings under the EnLink Revolving Credit Facility.

As of December 31, 2024, there were no remaining Series C Preferred Units outstanding.

Equity Issuances - On May 28, 2025, we completed the Delaware Basin JV Acquisition.

Pursuant to the purchase agreement, we issued approximately 4.9 million shares of ONEOK common stock to the seller with a fair value of $ 391 million as of the closing date.

On January 31, 2025, we completed the EnLink Acquisition.

We issued 41 million shares of common stock with a fair value of $ 4.0 billion.

There are no remaining Series B Preferred Units outstanding.

In September 2023, we completed the Magellan Acquisition.

Pursuant to the Magellan Merger Agreement, each common unit of Magellan was exchanged for a fixed ratio of 0.667 shares of ONEOK common stock and $ 25.00 of cash.

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approximately 135 million shares of common stock, with a fair value of approximately $ 9.0 billion as of the closing date of the Magellan Acquisition.

We have an “at-the-market” equity program for the offer and sale from time to time of our common stock up to an aggregate offering price of $ 1.0 billion.

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We are under no obligation to offer and sell common stock under the program.

31, 2024, no shares have been sold through our “at-the-market” program.

As of December 31, 2025, no shares have been sold through our “at-the-market” program.

Share Repurchase Program - In January 2024, our Board of Directors authorized a share repurchase program to buy up to $ 2.0 billion of our outstanding common stock.

We expect shares to be acquired from time to time in open market transactions or through privately negotiated transactions at our discretion, subject to market conditions and other factors.

The program will terminate upon completion of the repurchase of $ 2.0 billion of common stock or on Jan.

1, 2029, whichever occurs first.

31, 2024, we repurchased $ 172 million of our outstanding common stock under the program, which were funded by cash on hand and short-term borrowings.

Dividends - Holders of our common stock share equally in any dividend declared by our Board of Directors, subject to the rights of the holders of outstanding Series E Preferred Stock.

The program will terminate upon completion of the repurchase of the $ 2.0 billion of common stock or on January 1, 2029, whichever occurs first.

For the year ended December 31, 2025, we repurchased $ 62 million of our outstanding common stock under the program with cash on hand.

For the year ended December 31, 2024, we repurchased $ 172 million of our outstanding common stock under the program with cash on hand and short-term borrowings.

Dividends - Holders of our common stock share equally in any common stock dividends declared by our Board of Directors.

Dividends paid totaled $ 2.6 billion, $ 2.3 billion and $ 1.8 billion for 2025, 2024 and 2023, respectively.

The following table sets forth the quarterly dividends per share paid on our common stock in the periods indicated:

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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Total $ 4.12 $ 3.96 $ 3.82

Additionally, a common stock dividend of $ 1.03 per share ($ 4.12 per share on an annualized basis) was declared for shareholders of record at the close of business on Feb.

3, 2025, payable Feb.

Additionally, a quarterly common stock dividend of $ 1.07 per share ($ 4.28 per share on an annualized basis) was declared for shareholders of record at the close of business on February 2, 2026, and paid on February 13, 2026.

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VARIABLE INTEREST ENTITIES

Consolidated Variable Interest Entities (VIE)s - As of Dec.

31, 2024, we consolidate the following VIEs:

EnLink - We control EnLink through our ownership of its managing member.

EnLink is a VIE because the holders of the membership interest do not have substantive kick-out rights or participating rights over the managing member.

We are the primary beneficiary of EnLink because we have the power through our 100 % ownership of the managing member, to control decisions that most significantly impact EnLink.

We consolidate EnLink and record a noncontrolling interest for the interest that we do not own.

We also record a noncontrolling interest related to EnLink’s Series B Preferred Units.

Subsequent Event - Upon closing of the EnLink Acquisition on Jan.

31, 2025, EnLink is no longer considered a VIE.

Delaware Basin JV - EnLink owns a 50.1 % interest in the Delaware Basin JV, which owns processing facilities located in the Delaware Basin in Texas.

The Delaware Basin JV is a VIE because the other owner does not have substantive kick-out rights or participating rights over the managing member.

As the managing member, we are the primary beneficiary because we control the decisions that most significantly impact the Delaware Basin JV.

After June 30, 2025, our joint venture partner has the right to cause the Delaware Basin JV to commence a sale process to sell all of the outstanding interests or assets of the Delaware Basin JV for the best available price.

If our joint venture partner exercises this right, we are permitted to purchase their interest at a certain call price.

Ascension Pipeline Company, LLC (Ascension) - EnLink owns a 50 % interest in Ascension, which owns an NGL transmission pipeline that connects EnLink’s Riverside fractionator to the other owner’s refinery.

Ascension is a VIE because the other owner does not have the ability to remove us as the managing member.

Consolidated Variable Interest Entities (VIEs) - As of December 31, 2024, we consolidated EnLink, Delaware Basin JV and Ascension VIEs.

As a result of the Delaware Basin JV Acquisition and the EnLink Acquisition, these respective entities are no longer considered VIEs.

As of December 31, 2025, we consolidated the following VIEs:

MBTC Pipeline - On February 4, 2025, we announced a definitive agreement with MPLX LP to form the MBTC Pipeline joint venture, which will construct and operate a 24 -inch pipeline from our Mont Belvieu, Texas, storage facility to a new liquified petroleum gas export terminal in Texas City, Texas.

We own an 80 % interest in MBTC Pipeline, and we are the operator.

MBTC Pipeline is a VIE because the nonmanaging member does not have substantive rights (except in the case of default and other triggering events) to remove the managing member or participating rights over the managing member.

As the managing member, we are the primary beneficiary because we control the decisions that most significantly impact MBTC Pipeline.

Ascension - We own a 50 % interest in Ascension, which owns an NGL transmission pipeline that connects our Riverside fractionator to the other owner’s refinery.

Ascension is a VIE because the nonmanaging member does not have substantive rights (except in the case of default and other triggering events) to remove us as the managing member.

They also do not have the ability to participate or block our decisions as the managing member, which makes us the primary beneficiary because we control the decisions that most significantly impact Ascension.

The following table presents the balance sheet information for the assets and liabilities of our consolidated VIEs, which are included in our Consolidated Balance Sheet:

As of December 31, 2025, the assets and liabilities of our consolidated VIEs were not material.

The following table presents the balance sheet information for the assets and liabilities that are only for the use or obligation of our consolidated VIEs, which were included in our Consolidated Balance Sheets as of December 31, 2024:

(Millions of dollars)

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Other current assets 39

Property, plant and equipment, net 11,397

Net property, plant and equipment 11,397

Investments in unconsolidated affiliates 317

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Commodity imbalances 10

Accrued taxes 5

Accrued interest 73

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Other deferred credits 97

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EARNINGS PER SHARE

The following tables set forth the computation of basic and diluted EPS for the periods indicated:

Year Ended Dec.

Income Shares Per Share

Year Ended December 31, 2025

Income Shares Per Share Amount

(Millions, except per share amounts)

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Net income attributable to ONEOK available for common stock and common stock equivalents $ 3,393 625.9 $ 5.42

Year Ended Dec.

Income Shares Per Share

Year Ended December 31, 2024

Income Shares Per Share Amount

(Millions, except per share amounts)

Net income available for common stock $ 2,658 484.3 $ 5.49

Net income attributable to ONEOK available for common stock $ 3,034 584.6 $ 5.19

Effect of dilutive securities — 1.9

Net income available for common stock and common stock equivalents $ 2,658 485.4 $ 5.48

Year Ended Dec.

Income Shares Per Share

Net income attributable to ONEOK available for common stock and common stock equivalents $ 3,034 586.5 $ 5.17

Year Ended December 31, 2023

Income Shares Per Share Amount

(Millions, except per share amounts)

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SHARE-BASED PAYMENTS

Our Equity Incentive Plan (EIP) provides for the granting of stock-based compensation, including restricted stock unit awards and performance unit awards, to eligible employees and the granting of stock awards to non-employee directors.

We have reserved 8.5 million shares of common stock for issuance under the EIP and at Dec.

31, 2024, we had 3.2 million shares available for issuance under the plan.

Our Equity Incentive Plan (EIP) provides for the granting of stock-based compensation to eligible employees and non-employee directors, including restricted stock units, performance units, director stock awards and other awards.

In May 2025, our shareholders approved the 2025 Equity Incentive Plan (2025 EIP), which replaced the EIP approved by our shareholders in 2018.

All new equity awards are issued under the 2025 EIP.

There were 19.1 million shares of common stock authorized for issuance under the 2025 EIP and at December 31, 2025, we had 18.6 million shares available for issuance.

This calculation of available shares reflects shares issued and estimated shares expected to be issued upon vesting of outstanding awards granted under the 2025 EIP, excluding estimated forfeitures expected to be returned to the plan.

EnLink Controlling Interest Acquisition - As discussed in Note B, we completed the EnLink Controlling Interest Acquisition on Oct.

EnLink has previously issued restricted incentive units and performance units that vest at the end of a designated period, typically three years .

EnLink Acquisitions - As discussed in Note B, we completed the EnLink Controlling Interest Acquisition on October 15, 2024.

EnLink had previously issued restricted incentive units and performance units that vest at the end of a designated period, typically three years .

The fair value of these awards attributable to pre-combination service was allocated to consideration transferred and was included as part of the purchase price.

The portion attributable to post-combination service is being recognized as compensation expense on a straight-line basis over the remaining vesting period of the awards.

Compensation expense for the unit-based awards of EnLink for the ownership period is not material.

In addition, unrecognized compensation expense related to the outstanding EnLink restricted incentive units and performance units is not material.

Magellan Acquisition - As discussed in Note B, we completed the Magellan Acquisition on Sept.

Upon completion of the EnLink Acquisition on January 31, 2025, each outstanding unit-based award was converted into a restricted stock unit with respect to shares of our common stock and measured at their acquisition date fair value as if they were vested and issued on the acquisition date.

Converted restricted stock unit awards accrue dividend equivalents that are paid out in cash quarterly.

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Magellan Acquisition - As discussed in Note B, we completed the Magellan Acquisition on September 25, 2023.

Prior to the acquisition, Magellan had previously issued unit-based awards consisting of time-vested phantom units and performance phantom units, that vested at the end of a designated period, typically three years .

Pursuant to the terms of the Merger Agreement, each outstanding unit-based award was converted into a restricted stock unit and measured at their acquisition date fair value as if they were vested and issued on the acquisition date.

Pursuant to the terms of the Magellan Merger Agreement, each outstanding unit-based award was converted into a restricted stock unit with respect to shares of our common stock and measured at their acquisition date fair value as if they were vested and issued on the acquisition date.

The fair value attributable to pre-combination service was allocated to consideration transferred and was included as part of the purchase price.

The portion attributable to post-

combination service is being recognized as compensation expense on a straight-line basis over the remaining vesting period of the awards.

The portion attributable to post-combination service is being recognized as compensation expense on a straight-line basis over the remaining vesting period of the awards.

Converted restricted stock unit awards accrue dividend equivalents that are paid out in cash at vesting.

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Performance Unit Awards - We have granted performance unit awards to key employees that vest at the end of a three-year period.

Upon vesting, a holder of outstanding performance units is entitled to receive a number of shares of our common stock equal to a percentage ( 0 % to 200 %) of the performance units granted, based on our total shareholder return over the vesting period, compared with the total shareholder return of a peer group of other energy companies over the same period.

Upon vesting, a holder of outstanding performance units is entitled to receive a number of shares of our common stock equal to a percentage ( 0 % to 200 %) of the performance units granted, based on our total shareholder return over the performance period, compared with the total shareholder return of a peer group of other energy companies over the same period.

Performance unit awards are measured at fair value on the grant date based on a Monte Carlo model and adjusted for estimated forfeitures.

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Compensation expense is recognized on a straight-line basis over the vesting period of the award.

Stock Compensation for Non-Employee Directors - The EIP provides for the granting of nonstatutory stock options and stock bonus awards to non-employee directors, including performance unit awards and restricted stock unit awards.

Under the EIP, awards may be granted by the Executive Compensation Committee at any time, until grants have been made for all shares authorized under the EIP.

The maximum number of shares of common stock and cash-based awards that can be issued to a participant under the EIP during any year is limited to $ 0.8 million in value as of the grant date.

No performance unit awards or restricted stock unit awards have been made to non-employee directors, and there are no options outstanding.

Stock Compensation for Non-Employee Directors - The 2025 EIP provides for the granting of director stock awards and other awards to non-employee directors, up to $ 1.0 million per year for each such director when combined with any cash fees.

General - For all awards outstanding, we used a 3 % forfeiture rate based on historical forfeitures under our share-based payment plans.

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Compensation expense, exclusive of those recognized within transaction costs, for our share-based payment plans was $ 92 million, $ 102 million and $ 63 million during 2025, 2024 and 2023, respectively, before related tax benefits of $ 31 million, $ 36 million and $ 14 million, respectively.

Restricted Stock Unit Activity - As of Dec.

31, 2024, we had $ 43 million of total unrecognized compensation cost related to our nonvested restricted stock unit awards, which is expected to be recognized over a weighted-average period of 1.7 years.

Restricted Stock Unit Activity - As of December 31, 2025, we had $ 87 million of total unrecognized compensation cost related to our nonvested restricted stock unit awards, which is expected to be recognized over a weighted-average period of 1.9 years.

The following tables set forth activity and various statistics for our restricted stock unit awards:

Units Weighted

Average Price

Nonvested Dec.

31, 2023 (a) 1,724,565 $ 62.08

Granted 512,427 $ 75.42

of Units Weighted Average Price

Nonvested December 31, 2024 1,360,122 $ 68.71

Granted (a) 1,605,626 $ 88.80

Released to participants (b) ( 938,789 ) $ 75.33

( 808,544 ) $ 58.60

Forfeited (b) ( 77,622 ) $ 85.70

( 68,326 ) $ 71.14

Nonvested Dec.

31, 2024 (c) 1,360,122 $ 68.71

(a) - Includes 847,120 unvested restricted stock unit awards granted in conjunction with the Magellan Acquisition.

(b) - Includes 509,077 restricted stock unit awards released to participants and forfeited in conjunction with the Magellan Acquisition.

Nonvested December 31, 2025 1,949,337 $ 81.40

(a) - Included 480,280 unvested restricted stock unit awards converted in conjunction with the EnLink Acquisition.

(b) - Included 348,019 restricted stock unit awards released to participants and forfeited in conjunction with the EnLink Acquisition.

2025 2024 2023

Weighted-average grant date fair value (per share) $ 88.80 $ 75.42 $ 66.50

Fair value of units granted (millions of dollars) $ 39 $ 111 $ 20

Grant date fair value of units vested (millions of dollars) $ 47 $ 48 $ 14

Performance Unit Activity - As of Dec.

31, 2024, we had $ 38 million of tot al unrecognized compensation cost related to the nonvested performance unit awards, which is expected to be recognized over a weighted-average period of 1.8 years.

Grant date fair value of units granted (millions of dollars) $ 143 $ 39 $ 111

Table of C ontents

Performance Unit Activity - As of December 31, 2025, we had $ 39 million of tot al unrecognized compensation cost related to the nonvested performance unit awards, which is expected to be recognized over a weighted-average period of 1.7 years.

The following tables set forth activity and various statistics related to the performance unit awards and the assumptions used in the valuations at the respective grant dates:

Units Weighted

Average Price

Nonvested Dec.

31, 2023 1,094,940 $ 75.22

of Units Weighted Average Price

Nonvested December 31, 2024 1,099,699 $ 84.25

Granted 449,020 $ 80.55

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Forfeited ( 50,905 ) $ 84.55

Nonvested Dec.

31, 2024 1,099,699 $ 84.25

Nonvested December 31, 2025 1,165,108 $ 84.25

2025 2024 2023

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Weighted-average grant date fair value (per share) $ 80.55 $ 85.69 $ 87.46

Fair value of units granted (millions of dollars) $ 39 $ 32 $ 32

Grant date fair value of units vested (millions of dollars) $ 26 $ 21 $ 20

Grant date fair value of units granted (millions of dollars) $ 36 $ 39 $ 32

Employee Stock Purchase Plan - We have reserved a total of 13.1 million shares of common stock for issuance under our Employee Stock Purchase Plan (the ESPP).

Subject to certain exclusions, all employees are eligible to participate in the ESPP.

Employees can choose to have up to 10 % of their base pay withheld from each paycheck during the offering period to purchase our common stock, subject to terms and limitations of the plan.

Employees can choose to have up to 10 % of their base pay withheld from each paycheck during the offering period to purchase our common stock, subject to the terms and limitations of the plan.

The purchase price of the stock is 85 % of the lower of its grant date or exercise date market price.

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Under the plan, we sold 356,745 shares at a weighted average of $ 65.34 per share in 2025, 275,874 shares at a weighted average of $ 64.38 per share in 2024 and 236,108 shares at a weighted average of $ 52.70 per share in 2023.

Employee Stock Award Program - Under our Employee Stock Award Program, we issued, for no monetary consideration, to all eligible employees one share of our common stock when the per-share closing price of our common stock on the NYSE is at or above each one-dollar increment above its previous high closing price.

We originally reserved a total of 900,000 shares of common stock for issuance under this program.

Shares issued to employees under this program during 2024 totaled 127,825 and we have fully awarded all shares allocated to the program.

We expect to request additional shares be issued and allocated to the program during the 2025 Annual Meeting of Shareholders.

Employee Stock Award Program - Under our Employee Stock Award Program (the ESAP), we issued, for no monetary consideration, to all eligible employees one share of our common stock when the per-share closing price of our common stock on the NYSE is at or above each one-dollar increment above its previous high closing price.

We authorized a total of 900,000 shares of common stock under the ESAP.

The ESAP terminated as of November 7, 2024, and no additional grants were made under the program after such date.

In May 2025, our shareholders approved the 2025 Employee Stock Award Program (the 2025 ESAP), which issues shares of our common stock in the same manner as the ESAP and permits our Board of Directors to issue additional shares of our common stock in its discretion.

A total of 700,000 shares of common stock were authorized for issuance under the 2025 ESAP.

Shares issued to employees under these programs during 2025 and 2024 totaled 66,916 and 127,825 , respectively.

Employees have received awards through the $ 117 milestone.

No shares were issued to employees under this program in 2023 or 2022.

No shares were issued to employees under these programs in 2023.

Deferred Compensation Plan for Non-Employee Directors - Our Deferred Compensation Plan for Non-Employee Directors provides our non-employee directors the option to defer all or a portion of their compensation for their service on our Board of Directors.

Under the plan, directors may elect either a cash deferral option or a phantom stock option.

Under the cash deferral option, directors may elect to defer the receipt of all or a portion of their annual retainer fees, which will be credited with interest during the deferral period.

Under the phantom stock option, directors may defer all or a portion of their annual retainer fees and receive such fees on a deferred basis in the form of shares of common stock under our EIP, which earn the equivalent of dividends declared on our common stock.

Under the cash deferral option, directors may elect to defer the receipt of all or a portion of their annual retainer fees (other than their stock retainer fees), which will be credited with interest during the deferral period.

Under the phantom stock option, directors may defer all or a portion of their annual retainer fees and receive such fees on a deferred basis in the form of shares of common stock under our EIP or 2025 EIP, which earn the equivalent of dividends declared on our common stock.

Shares are distributed to non-employee directors at the fair market value of our common stock at the date of distribution.

Table of C ontents

EMPLOYEE BENEFIT PLANS

Retirement and Other Postretirement Benefit Plans

ONEOK Legacy Retirement Plan - We have a legacy defined benefit pension plan covering certain employees and former employees, which closed to new participants in 2005.

In addition, we have a supplemental executive retirement plan for the benefit of certain officers who participate in our defined benefit pension plan.

ONEOK Retirement Plan - We maintain the ONEOK Retirement Plan, a defined benefit pension plan covering certain legacy ONEOK employees, which closed to new participants in 2005.

In addition, we have a supplemental executive retirement plan for the benefit of certain officers who participate in the ONEOK Retirement Plan.

Our supplemental executive retirement plan is closed to new participants.

We fund our defined benefit pension plan at a level needed to maintain or exceed the minimum funding levels required by the Employee Retirement Income Security Act of 1974, as amended.

Magellan Legacy Retirement Plans - As a result of the Magellan Acquisition, we assumed the pension plan assets and obligations of Magellan in 2023.

These obligations are composed of two defined benefit pension plans, including one for non-union employees and one for union employees.

The pension plan for non-union employees closed to new participants upon the closing of the acquisition.

The pension plan for union employees closed to new participants in January 2024.

Magellan Retirement Plans - As a result of the Magellan Acquisition in 2023, we assumed two defined benefit pension plans covering certain legacy Magellan employees, including the Magellan Pension Plan, which closed to new participants upon the closing of the acquisition, and the Magellan Pension Plan for USW Employees, which closed to new participants in January 2024.

We fund these defined benefit pension plans at a level needed to maintain or exceed the minimum funding levels required by the Employee Retirement Income Security Act of 1974, as amended.

Other Postretirement Benefit Plans - We sponsor legacy health and welfare plans that provide postretirement medical and life insurance benefits to employees hired prior to 2017 who retire with at least five years of full-time consecutive service.

Other Postretirement Benefit Plans - We sponsor health and welfare plans that provide postretirement medical and life insurance benefits to certain legacy ONEOK employees hired prior to 2017 and certain legacy Magellan employees who retire after a specified age with at least five years of service and satisfy certain other conditions.

The postretirement medical plan for pre-Medicare participants is contributory, with retiree contributions adjusted periodically, and contains other cost-sharing features such as deductibles and coinsurance.

The postretirement medical plan for Medicare-eligible participants is an account-based plan under which participants may elect to purchase private insurance policies under a private exchange and/or seek reimbursement of other eligible medical expenses.

In 2023, we also assumed the postretirement benefit obligations of Magellan which covers certain employees of Magellan.

Obligations and Funded Status - The following table sets forth our retirement and other postretirement benefit plans benefit obligations and fair value of plan assets for the periods indicated:

Retirement Benefits Other Postretirement Benefits

December 31, December 31,

2025 2024 2025 2024

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Plan participants’ contributions — — 1 1

Actuarial (gain) loss

Actuarial loss (gain)

2 ( 35 ) ( 1 ) ( 5 )

Benefits paid ( 38 ) ( 36 ) ( 4 ) ( 3 )

Magellan Acquisition

Benefit obligation, end of period (a) 707 689 45 46

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Benefits paid ( 38 ) ( 36 ) ( 4 ) ( 3 )

Magellan Acquisition

Fair value of plan assets, end of period (b) 586 535 14 15

Balance at Dec.

$ ( 154 ) $ ( 148 ) $ ( 31 ) $ ( 35 )

Balance at December 31 $ ( 121 ) $ ( 154 ) $ ( 31 ) $ ( 31 )

Current liabilities $ ( 5 ) $ ( 5 ) $ — $ —

Noncurrent liabilities ( 116 ) ( 149 ) ( 31 ) ( 31 )

Balance at Dec.

$ ( 154 ) $ ( 148 ) $ ( 31 ) $ ( 35 )

(a) - The benefit obligation for Retirement Benefits at Dec.

31, 2024 and 2023, include the supplemental executive retirement plan obligation.

(b) - Fair value of plan assets for Retirement Benefits exclude the assets of our supplemental executive retirement plan, which totaled $ 92 million and $ 89 million at Dec.

31, 2024 and 2023, respectively, and are included in other assets on the Consolidated Balance Sheets.

Balance at December 31 $ ( 121 ) $ ( 154 ) $ ( 31 ) $ ( 31 )

(a) - The benefit obligation for Retirement Benefits at December 31, 2025 and 2024, included the supplemental executive retirement plan obligation.

(b) - Fair value of plan assets for Retirement Benefits excluded the assets of our supplemental executive retirement plan, which totaled $ 90 million and $ 92 million at December 31, 2025 and 2024, respectively, and are included in other assets on the Consolidated Balance Sheets.

These assets are maintained in a rabbi trust and are not treated as assets of the supplemental executive retirement plan.

The accumulated benefit obligation for our retirement plans was $ 628 million and $ 637 million at Dec.

31, 2024 and 2023, respectively.

Table of C ontents

The accumulated benefit obligation for our retirement plans was $ 648 million and $ 628 million at December 31, 2025 and 2024, respectively.

The components of net periodic benefit cost and related assumptions, and amounts recognized in other comprehensive income related to our retirement and other postretirement benefit plans are not material.

The balance in accumulated other comprehensive loss at Dec.

31, 2024 and 2023, was $ 58 million and $ 64 million, respectively.

The balance in accumulated other comprehensive loss at December 31, 2025 and 2024, was $ 46 million and $ 58 million, respectively.

This balance is expected to be amortized over the average remaining service period of employees participating in these plans.

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Retirement Benefits Other Postretirement Benefits

December 31, December 31,

2025 2024 2025 2024

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The goal of this strategy is to maximize investment returns while managing risk in order to meet the plan’s current and projected financial obligations.

The investment allocation for our ONEOK legacy defined benefit pension plan follows a glide path approach of liability-driven investing that shifts a higher portfolio weighting to fixed income as the plan’s funded status increases.

A majority of the legacy Magellan pension assets are allocated to fixed income securities and invested to match the duration of the plans’ short, intermediate and long-term liabilities, with the remaining amount allocated to equity securities.

The investment allocation for our ONEOK Retirement Plan follows a glide path approach of liability-driven investing that shifts a higher portfolio weighting to fixed income as the plan’s funded status increases.

A majority of the assets of the Magellan Pension Plan and the Magellan Pension Plan for USW Employees are allocated to fixed income securities and invested to match the duration of the plans’ short, intermediate and long-term liabilities, with the remaining amount allocated to equity securities.

Our pension plans utilize a diversified mix of investments that may include domestic and international equities, short, intermediate and long-term corporate and government obligations, real estate and hedge funds.

The combined target allocation for the assets of our pension plans as of Dec.

31, 2024, is as follows:

The combined target allocation for the assets of our pension plans as of December 31, 2025, is as follows:

Domestic and international equities 30 %

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As part of our risk management for the plans, minimums and maximums have been set for each of the asset classes listed above.

The fair value of the plan assets for our other postretirement benefit plans as of Dec.

31, 2024, are not material.

Table of C ontents

The fair value of the plan assets for our other postretirement benefit plans as of December 31, 2025, are not material.

The following tables set forth the plan assets by fair value category as of the measurement date for our defined benefit pension plans:

Pension Benefits

Asset Category Level 1 Level 2 Level 3 Subtotal Measured at NAV (d)

December 31, 2025

Asset Category Level 1 Level 2 Level 3 Subtotal Measured at NAV (d) Total

( Millions of dollars )

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(c) - This category repre sen ts alternative investments in limited partnerships, which can be redeemed with a 30-day notice with no further restrictions.

There are no unfunded capital commitments.

There were no unfunded capital commitments.

These limited partnerships invest through multi-strategy programs in broadly diversified portfolios of private investment funds, hedge funds and/or separate accounts to seek equity-like returns with low market correlation, reduced volatility and limited risk.

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Pension Benefits

Asset Category Level 1 Level 2 Level 3 Subtotal Measured at NAV (d)

December 31, 2024

Asset Category Level 1 Level 2 Level 3 Subtotal Measured at NAV (d) Total

( Millions of dollars )

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(c) - This category repre sen ts alternative investments in limited partnerships, which can be redeemed with a 30-day notice with no further restrictions.

There are no unfunded capital commitments.

There were no unfunded capital commitments.

(d) - Plan asset investments measured at fair value using the net asset value per share.

Contributions - During 2024, we contributed $ 5 million to our legacy ONEOK defined benefit pension and made no contributions to our legacy Magellan defined benefit pension plans and other post retirement benefit plans.

We contributed $ 9 million to our legacy ONEOK defined benefit pension, $ 17 million to our legacy Magellan non-union plan and $ 3 million to

our legacy Magellan union plan in February 2025.

We do not expect to make any contributions to our other postretirement benefit plans in 2025.

Pension and Other Postretirement Benefit Payments - Benefit payments for our defined benefit pensions and other postretirement benefit plans for the period ending Dec.

31, 2024, were $ 36 million and $ 3 million, respectively.

Table of C ontents

Contributions - During 2025, we contributed $ 9 million to our ONEOK Retirement Plan, $ 17 million to our Magellan Pension Plan and $ 3 million to our Magellan Pension Plan for USW Employees, all of which were related to the 2024 plan year.

We do not expect contributions to our defined benefit pension plans to be material in 2026.

We do not expect to make any contributions to other postretirement benefit plans in 2026.

Pension and Other Postretirement Benefit Payments - Benefit payments for our defined benefit pensions and other postretirement benefit plans for the period ending December 31, 2025, were $ 38 million and $ 4 million, respectively.

The following table sets forth the defined benefit pension and other postretirement benefits payments expected to be paid in 2026 through 2035:

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2031 through 2035 $ 280 $ 17

The expected benefits to be paid are based on the same assumptions used to measure our benefit obligation at Dec.

31, 2024, and include estimated future employee service.

The expected benefits to be paid are based on the same assumptions used to measure our benefit obligation at December 31, 2025, and include estimated future employee service.

Other Employee Benefit Plans

401(k) Plan - We have a 401(k) Plan covering all employees, and employee contributions are discretionary.

We match 100 % of employee 401(k) Plan contributions up to 6 % of each participant’s eligible compensation each payroll period, subject to certain limits.

401(k) Plan - The ONEOK 401(k) Plan covers all employees, and employee contributions are discretionary.

We match 100 % of employee 401(k) Plan contributions up to 6 % of each participant’s eligible compensation, subject to certain conditions and limits.

We also make profit-sharing contributions under our 401(k) Plan for employees who do not participate in our defined benefit pension plans.

We generally make a quarterly profit-sharing contribution equal to 1 % of each profit-sharing participant’s eligible compensation during the quarter and an annual discretionary profit-sharing contribution equal to a percentage of each profit-sharing participant’s eligible compensation.

Effective Jan.

1, 2025, the profit-sharing quarterly contributions will increase to 6 % from 1 % of quarterly eligible compensation.

We will continue to make annual discretionary contributions of up to 2 % of eligible compensation.

Effective January 1, 2025, quarterly profit-sharing contributions increased to 6 % from 1 % of each profit-sharing participant’s eligible compensation during the quarter.

We may also make annual discretionary profit-sharing contributions of up to 2 % of eligible compensation.

Our contributions made to the plan, including profit-sharing contributions, were $ 128 million, $ 66 million and $ 44 million in 2025, 2024 and 2023, respectively.

Medallion terminated the legacy Medallion 401(k) Plan effective Oct.

30, 2024, prior to the closing of the Medallion Acquisition on Oct.

Legacy Medallion employees may roll their Medallion 401(k) Plan account balance to the ONEOK 401(k) Plan or an individual retirement account or take a distribution.

In September 2023, the legacy Magellan 401(k) Plan was terminated as a result of the Magellan Acquisition, and legacy Magellan employees were given the option to roll their 401(k) balances into the existing ONEOK 401(k) Plan or to their individual retirement accounts.

EnLink terminated the EnLink 401(k) Plan effective January 30, 2025, prior to the closing of the EnLink Acquisition.

Legacy EnLink employees were permitted to roll their EnLink 401(k) Plan account balance to the ONEOK 401(k) Plan, an individual retirement account or take a distribution.

The EnLink 401(k) Plan was liquidated and closed in December 2025.

Medallion terminated the Medallion 401(k) Plan effective October 30, 2024, prior to the closing of the Medallion Acquisition on October 31, 2024.

Legacy Medallion employees were permitted to roll their Medallion 401(k) Plan account balance to the ONEOK 401(k) Plan or an individual retirement account or take a distribution.

The Medallion 401(k) Plan was liquidated and closed in September 2025.

Magellan terminated the Magellan 401(k) Plan effective September 24, 2023, prior to the closing of the Magellan Acquisition.

Legacy Magellan employees were given the option to roll their Magellan 401(k) Plan account balance to the ONEOK 401(k) Plan or an individual retirement account or take a distribution.

The Magellan 401(k) Plan was liquidated and closed in September 2024.

Subsequent event - EnLink terminated the EnLink 401(k) Plan effective Jan.

30, 2025, prior to the closing of the EnLink Acquisition.

Legacy EnLink employees may roll their EnLink 401(k) Plan account balance to the ONEOK 401(k) Plan, an individual retirement account or take a distribution.

Nonqualified Deferred Compensation Plan - The 2020 Nonqualified Deferred Compensation Plan and its predecessor nonqualified deferred compensation plans (collectively, the NQDC Plan) provide a select group of management and highly compensated employees, as approved by our chief executive officer, with the option to defer portions of their compensation and receive notional employer contributions that generally are not available due to limitations on employer and employee contributions to qualified defined contribution plans under federal tax laws.

Our investments which are included in other assets on the Consolidated Balance Sheets related to the NQDC Plan are not material.

Our investments which are included in other assets on the Consolidated Balance Sheets related to the NQDC Plan were not material.

These investments are maintained in a rabbi trust.

Our contributions to the plan were not material.

Table of C ontents

The following table sets forth our provision for income taxes for the periods indicated:

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

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The following table is a reconciliation of our income tax provision for the periods indicated:

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

( Millions of dollars )

(Millions of dollars, except for percentages)

Income before income taxes

2 unchanged sentences

Provision for federal income taxes 943 21.0 % 863 21.0 % 734 21.0 %

State income taxes, net of federal benefit 93 100 54

Change in valuation allowance

Deferred tax rate change

Excess tax benefits from share-based compensation ( 13 ) 1 ( 1 )

State income taxes, net of federal tax benefit (a) 91 2.0 % 125 3.0 % 102 2.9 %

Nontaxable or nondeductible items ( 6 ) ( 0.1 ) % 3 0.1 % ( 1 ) — %

Other, net — — % 7 0.2 % 3 0.1 %

Income tax provision $ 1,028 22.9 % $ 998 24.3 % $ 838 24.0 %

(a) - Our operations are primarily apportioned across Oklahoma, Texas, Kansas and North Dakota for state income tax purposes.

(b) - Represents percent of income before income taxes.

The following table sets forth cash paid for income taxes, net of refunds, for the periods indicated:

Years Ended December 31,

2025 2024 2023

(Millions of dollars)

Federal $ 52 $ 85 $ 27

State 22 17 10

Total cash paid for income taxes, net of refunds $ 74 $ 102 $ 37

Table of C ontents

The following table sets forth the tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and liabilities as of the dates indicated:

2025 December 31,

Deferred tax assets ( Millions of dollars )

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Federal net operating loss 2,570 2,818

Federal tax credit 6 —

State net operating loss and benefits 546 515

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(a) Due primarily to excess of tax over book depreciation.

15, 2024, we completed the EnLink Controlling Interest Acquisition resulting in a difference between the carrying value of the underlying assets acquired and the carryover tax basis in the assets, which resulted in a deferred tax liability of $ 2.0 billion recorded as part of the purchase price allocation.

Subsequent event - On Jan.

31, 2025, we completed the EnLink Acquisition by acquiring all of the remaining and outstanding publicly held EnLink Units.

On January 31, 2025, we completed the EnLink Acquisition by acquiring all of the remaining and outstanding publicly held EnLink Units.

EnLink is now a wholly owned subsidiary and included in our consolidated income tax returns.

31, 2024, we have federal net operating loss carryforwards of $ 13.4 billion, the majority of which have an indefinite carryforward period.

As of December 31, 2025, we have federal net operating loss carryforwards of $ 12.2 billion, which have an indefinite carryforward period.

We expect to generate taxable income and utilize these net operating loss carryforwards in future periods.

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We believe that it is more likely than not that the tax benefits of certain state carryforwards will not be utilized;

therefore, we recorded a valuation allowance, which was increased by $ 12 million and $ 165 million in 2024 and 2023, respectively, a nd reduced by $ 1 million in 2022 through net income.

therefore, we recorded a valuation allowance, which was increased by $ 15 million, $ 12 million and $ 165 million in 2025, 2024 and 2023, respectively, through net income.

Table of C ontents

UNCONSOLIDATED AFFILIATES

EnLink Controlling Interest Acquisition - As a result of the EnLink Controlling Interest Acquisition, our investments in unconsolidated affiliates includes EnLink’s three unconsolidated affiliates.

These investments include EnLink’s 15 % ownership interest in Matterhorn, which is a bidirectional pipeline that transports natural gas from the Waha Hub to Katy, Texas.

The other unconsolidated affiliates acquired are not material.

Investments in Unconsolidated Affiliates - The following table sets forth our investments in unconsolidated affiliates as of the dates indicated:

Interest Dec.

Net Ownership Interest December 31,

2025 December 31, 2024

(Millions of dollars)

Overland Pass 50 % $ 400 $ 402

Saddlehorn (a) 40 % 373 288

BridgeTex (a) 60 % $ 504 $ 250

Northern Border 50 % 444 333

BridgeTex 30 % 250 193

Overland Pass 50 % 391 400

Saddlehorn 40 % 361 373

Matterhorn (b) 15 % 272 248

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Roadrunner 50 % 181 183

Texas City Logistics 50 % 162 —

Other Various 346 294

Investments in unconsolidated affiliates (c) $ 2,889 $ 2,316

(a) - In March 2024, we purchased an additional 10 % interest in Saddlehorn, resulting in a 40 % ownership interest.

(b) - As of Dec.

31, 2024, the 15 % interest represents EnLink’s ownership interest in Matterhorn.

31, 2024 and 2023, respectively, related to property, plant and equipment and equity-method goodwill (Note A).

(a) - In July 2025, we purchased an additional 30 % interest in BridgeTex, resulting in a 60 % ownership interest.

(b) - As of December 31, 2025, the 15 % interest represented ONEOK’s ownership interest in Matterhorn as a result of the EnLink Acquisition on January 31, 2025.

As of December 31, 2024, the 15 % interest represented EnLink’s ownership interest in Matterhorn.

(c) - Included basis differences of $ 431 million and $ 368 million at December 31, 2025, and 2024, respectively, related to property, plant and equipment and equity-method goodwill (Note A).

Equity in Net Earnings from Investments - The following table sets forth our equity in net earnings from investments for the periods indicated:

Years Ended Dec.

Years Ended December 31,

2025 2024 2023

(Millions of dollars)

BridgeTex (a) $ 127 $ ( 1 ) $ —

Northern Border $ 105 $ 95 $ 75

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Saddlehorn (a) 50 50 10

BridgeTex (a)(c) 41 127 ( 1 )

Roadrunner 41 40 43

MVP (a) 14 4 —

Matterhorn (b) 24 8 —

MVP (a) 13 14 4

Other 21 19 15

Equity in net earnings from investments $ 386 $ 439 $ 202

(a) - For the year ended Dec.

31, 2023, includes equity in net earnings from the period Sept.

25, 2023 through Dec.

(b) - For the year ended Dec.

31, 2024, includes equity in net earnings from the period Oct.

15, 2024 through Dec.

We incurred expenses in transactions with unconsolidated affiliates of $ 254 million, $ 132 million and $ 83 million for 2024, 2023 and 2022, respectively, primarily related to Overland Pass and Northern Border.

Revenue earned and accounts receivable from, and accounts payable to, our equity-method investees were not material.

(a) - The year ended December 31, 2023, included equity in net earnings from the period September 25, 2023, through December 31, 2023.

(b) - The year ended December 31, 2024, included equity in net earnings from the period October 15, 2024, through December 31, 2024.

(c) - The year ended December 31, 2024, included equity in net earnings of $ 88 million on BridgeTex associated with the nonrecurring recognition of deferred revenue.

We incurred expenses in transactions with unconsolidated affiliates of $ 280 million, $ 254 million and $ 132 million for 2025, 2024 and 2023, respectively, primarily related to Overland Pass, Matterhorn and Northern Border.

Revenue earned and accounts receivable from, and accounts payable to, our unconsolidated affiliates were not material.

We have agreements with our unconsolidated affiliates which provide that distributions to members are made, primarily, on a pro rata basis according to each member’s ownership interest.

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Reimbursements and payments included in operating income in our Consolidated Statements of Income for all periods presented were not material.

Table of C ontents

In 2025, we, WhiteWater, MPLX LP and Enbridge Inc., through the existing Matterhorn joint venture, announced the new approximately 450 -mile, 48 -inch Eiger Express Pipeline, designed to transport up to approximately 3.7 Bcf/d of natural gas from the Permian Basin to Katy, Texas.

WhiteWater will construct and operate the pipeline.

Our total ownership interest in the pipeline will be 25.5 %, which includes a 15 % interest held directly in the Eiger joint venture with the remainder held through Matterhorn.

Our investment in Eiger is accounted for using the equity method as we have the ability to exercise significant influence over the operating and financial policies of Eiger, although we do not have the ability to exercise control.

On July 22, 2025, we completed the BridgeTex Additional Interest Acquisition.

Pursuant to the purchase agreement, we paid approximately $ 270 million in cash, which we funded with short-term borrowings.

Following the completion of the transaction, we now have a 60 % ownership interest in BridgeTex.

Our investment in BridgeTex continues to be accounted for using the equity method as we continue to have the ability to exercise significant influence over the operating and financial policies of BridgeTex, although we do not have the ability to exercise control.

On February 4, 2025, we announced definitive agreements to form joint ventures with MPLX LP to construct a 400 MBbl/d liquified petroleum gas export terminal in Texas City, Texas, and a new 24 -inch pipeline from our Mont Belvieu, Texas, storage facility to the new terminal.

Texas City Logistics, the export terminal joint venture, is owned 50 % by us and 50 % by MPLX LP, with MPLX LP constructing and operating the facility.

Our investment in Texas City Logistics is accounted for using the equity method as we have the ability to exercise significant influence over the operating and financial policies of Texas City Logistics, although we do not have the ability to exercise control.

In 2025, we made equity contributions to Texas City Logistics and Northern Border of $ 160 million and $ 101 million, respectively, which, in combination with equal contributions from our joint venture partners, were primarily used for funding capital projects.

In 2024, we acquired an additional 10 % interest in Saddlehorn, resulting in a total ownership interest of 40 %.

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Also in 2023, we made an equity contribution of $ 91 million to Northern Border, which, in combination with an equal contribution from our joint venture partner, was used to partially repay the outstanding balance of its revolving credit facility and fund capital projects.

In 2022, our equity contributions were not material.

COMMITMENTS AND CONTINGENCIES

Commitments - The following table sets forth our transportation, volume and storage commitments for the periods indicated:

( Millions of dollars )

Commitments ( Millions of dollars )

Thereafter 870

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Failure to comply with these laws and regulations may trigger a variety of administrative, civil and potentially criminal enforcement measures, including citizen suits, which can include the assessment of monetary penalties, the imposition of remedial requirements and the issuance of injunctions or restrictions on operation or construction.

Management does not

believe that, based on currently known information, a material risk of noncompliance with these laws and regulations exists that will affect adversely our consolidated results of operations, financial condition or cash flows.

Legal Proceedings - Corpus Christi Terminal Personal Injury Proceeding - Ismael Garcia, Andrew Ramirez, and Jesus Juarez Quintero, et al.

brought personal injury cases against Magellan and co-defendants Triton Industrial Services, LLC, Tidal Tank, Inc.

and Cleveland Integrity Services, Inc.

in Nueces County Court in Texas.

The claims were originally brought in three different actions but were consolidated into a single case on Mar.

Claims were asserted by or on behalf of seven individuals, and certain beneficiaries, who were employed by a contractor of Magellan and were injured, one fatally, as a result of a fire that occurred on Dec.

5, 2020, while they were cleaning a tank at our Corpus Christi terminal.

In 2024, we reached settlement with all remaining claimants, and all settlement payments were made, and were fully offset by insurance proceeds received.

We are a party to various other legal proceedings that have arisen in the normal course of our operations.

Management does not believe that, based on currently known information, a material risk of noncompliance with these laws and regulations exists that will adversely affect our consolidated results of operations, financial condition or cash flows.

Legal Proceedings - We are a party to various legal proceedings that have arisen in the normal course of our operations.

While the results of these proceedings cannot be predicted with certainty, we believe the reasonably possible losses from such proceedings, individually and in the aggregate, are not material.

Additionally, we believe the probable final outcome of such proceedings will not have a material adverse effect on our consolidated results of operations, financial position or cash flows.

Table of C ontents

Lessee activity - The following table sets forth information about our operating lease assets and liabilities included in our Consolidated Balance Sheets as of the dates indicated:

Leases Location in our Consolidated Balance Sheets Dec.

31, 2024 Dec.

Leases Location in our Consolidated Balance Sheets December 31,

2025 December 31,

( Millions of dollars )

Operating leases assets Other assets $ 220 $ 104

Operating leases liabilities

Operating lease assets

Other assets $ 245 $ 220

Operating lease liabilities

Current Other current liabilities

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Total operating lease liabilities

The weighted average remaining lease term for our operating leases was 9.1 years and 6.3 years at Dec.

31, 2024 and 2023, respectively.

The weighted average discount rate for our operating leases was 5.51 % and 5.78 % at Dec.

31, 2024 and 2023, respectively.

The weighted average remaining lease term for our operating leases was 11.0 years and 9.1 years at December 31, 2025 and 2024, respectively.

The weighted average discount rate for our operating leases was 5.52 % and 5.51 % at December 31, 2025 and 2024, respectively.

Our weighted-average discount rates represent the rate implicit in the lease or our incremental borrowing rate for a term equal to the remaining term of the lease.

The following table sets forth the maturity of our lease liabilities as of Dec.

The following table sets forth the maturity of our lease liabilities as of December 31, 2025:

( Millions of dollars )

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Present value of lease liabilities $ 237

Our lease costs and supplemental cash flow information related to our leases for the periods ended Dec.

31, 2024 and 2023, are not material.

Our lease costs and supplemental cash flow information related to our leases for the periods ended December 31, 2025 and 2024, are not material.

Unsatisfied Performance Obligations - We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) variable consideration on contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed.

The following table presents aggregate value allocated to unsatisfied performance obligations as of Dec.

31, 2024, and the amounts we expect to recognize in revenue in future periods, related primarily to firm transportation and storage contracts with remaining contract terms ranging from two months to 16 years:

The following table presents aggregate value allocated to unsatisfied performance obligations as of December 31, 2025, and the amounts we expect to recognize in revenue in future periods, related primarily to firm transportation and storage contracts with remaining contract terms ranging from one month to 20 years:

Expected Period of Recognition in Revenue ( Millions of dollars )

2030 and beyond 2,810

Total estimated transaction price allocated to unsatisfied performance obligations $ 7,512

The table above excludes variable consideration allocated entirely to wholly unsatisfied performance obligations, wholly unsatisfied promises to transfer distinct goods or services that are part of a single performance obligation and consideration we determine to be fully constrained.

Total $ 7,061

Table of C ontents

determine to be fully constrained.

Information on the nature of the variable consideration excluded and the nature of the performance obligations to which the variable consideration relates can be found in the description of the major contract types discussed in Note A.

The amounts we determined to be fully constrained relate to future sales obligations under long-term sales contracts where the value is not known and minimum volume agreements, which we consider to be fully constrained until invoiced.

The amounts we determined to be fully constrained relate to future sales obligations under long-term sales contracts where the value is not known and certain minimum volume agreements, which we consider to be fully constrained until invoiced.

Segment Descriptions - Our operations are divided into four reportable business segments, as follows:

• our Natural Gas Gathering and Processing segment gathers, treats, processes and markets natural gas;

• our Natural Gas Gathering and Processing segment gathers, compresses, treats, processes and markets natural gas;

• our Natural Gas Liquids segment gathers, treats, fractionates and transports NGLs and stores, markets and distributes Purity NGLs;

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• our Refined Products and Crude segment gathers, transports, stores, distributes, blends and markets Refined Products and crude oil.

15, 2024, we completed the EnLink Controlling Interest Acquisition.

EnLink’s results of operations are reported across all four of our existing operating segments from the period of Oct.

15, 2024, to Dec.

31, 2024, we completed the Medallion Acquisition.

Medallion’s results of operations are reported in our Refined Products and Crude segment from the period of Nov.

1, 2024, to Dec.

On October 15, 2024, we completed the EnLink Controlling Interest Acquisition.

Our 2024 results include the impact of the EnLink Controlling Interest Acquisition from the period of October 15, 2024, to December 31, 2024, across all four of our existing operating segments.

On October 31, 2024, we completed the Medallion Acquisition.

Our 2024 results include the impact of the Medallion Acquisition from the period of November 1, 2024, to December 31, 2024, in our Refined Products and Crude segment.

Other and eliminations consist of corporate costs, the operating activities of our headquarters building and related parking facility, the activity of our wholly owned captive insurance company and eliminations necessary to reconcile our reportable segments to our Consolidated Financial Statements.

For the years ended Dec.

31, 2024, and Dec.

31, 2022, we had no single customer from which we received 10% or more of our consolidated revenues.

For the year ended Dec.

31, 2023, revenues from one customer impacting all our segments represented approximately 11 % of our consolidated revenues.

For the years ended December 31, 2025, and December 31, 2023, revenues from one customer impacting all our segments represented approximately 12 % and 11 % of our consolidated revenues, respectively.

For the year ended December 31, 2024, we had no single customer from which we received 10% or more of our consolidated revenues.

The significant expense categories and amounts included in the table below align with the segment-level information that is regularly provided to the chief operating decision-maker.

Table of C ontents

Operating Segment Information - The following tables set forth certain selected financial information for our operating segments for the periods indicated:

Year Ended Dec.

31, 2024 Natural Gas

Gathering and

Processing Natural Gas

Liquids Natural Gas

Pipelines Refined Products and Crude Total

Year Ended December 31, 2025 Natural Gas Gathering and Processing Natural Gas Liquids Natural Gas Pipelines Refined Products and Crude Total Segments

(Millions of dollars)

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Other revenue 38 11 — 117 166

23 14 1 120 158

Total revenues (a) 7,684 16,010 1,846 13,039 38,579

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Adjusted EBITDA from unconsolidated affiliates 5 101 244 166 516

3 95 187 247 532

Noncash compensation expense

20 34 8 31 93

75 3 228 ( 9 ) 297

Noncash compensation expense and other 54 32 7 49 142

Segment adjusted EBITDA $ 2,138 $ 2,779 $ 861 $ 2,177 $ 7,955

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Intersegment revenues totaled $ 4.3 billion for the Natural Gas Gathering and Processing segment, $ 0.5 billion for the Natural Gas Liquids segment and were not material for the Refined Products and Crude and Natural Gas Pipelines segments.

(b) - Includes a gain of $ 227 million for the Natural Gas Pipelines segment related to the sale of three of our wholly owned interstate natural gas pipeline systems to DT Midstream, Inc.

Year Ended Dec.

31, 2024 Total

Segments Other and

Eliminations Total

Year Ended December 31, 2025 Total Segments Other and Eliminations Total

(Millions of dollars)

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Other revenue 166 ( 22 ) 144

158 ( 20 ) 138

Total revenues (a) $ 38,579 $ ( 4,950 ) $ 33,629

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Capital expenditures $ 3,061 $ 91 $ 3,152

(a) - Substantially all of our revenues relate to contracts with customers.

Year Ended Dec.

31, 2023 Natural Gas

Gathering and

Processing Natural Gas

Liquids Natural Gas

Pipelines Refined Products and Crude Total

(a) - Substantially all of our revenues are related to contracts with customers.

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Year Ended December 31, 2024 Natural Gas Gathering and Processing Natural Gas Liquids Natural Gas Pipelines Refined Products and Crude Total Segments

(Millions of dollars)

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Residue natural gas sales 1,203 — 137 — 1,340

Gathering, processing and exchange services revenue 147 549 — — 696

Exchange services and natural gas gathering and processing revenue 260 500 — — 760

Transportation and storage revenue 70 207 684 2,082 3,043

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Noncash compensation expense 20 34 8 31 93

( 1 ) 778 ( 2 ) — 775

Other (b) 75 3 228 ( 9 ) 297

Segment adjusted EBITDA $ 1,484 $ 2,543 $ 900 $ 1,892 $ 6,819

$ 1,244 $ 3,045 $ 559 $ 465 $ 5,313

Depreciation and amortization $ ( 325 ) $ ( 361 ) $ ( 88 ) $ ( 354 ) $ ( 1,128 )

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(a) - Intersegment revenues are primarily from commodity sales, which are based on the contracted selling price that is generally index-based and settled monthly.

Intersegment revenues for the Natural Gas Gathering and Processing segment totaled $ 2.4 billion and were not material for the Natural Gas Liquids, Refined Products and Crude and Natural Gas Pipelines segments.

(b) - Includes a settlement gain of $ 779 million for the Natural Gas Liquids segment related to the Medford incident.

Year Ended Dec.

31, 2023 Total

Segments Other and

Eliminations Total

Intersegment revenues totaled $ 3.0 billion for the Natural Gas Gathering and Processing segment, $ 0.3 billion for the Natural Gas Liquids segment and were not material for the Refined Products and Crude and Natural Gas Pipelines segments.

(b) - Included a gain of $ 227 million for the Natural Gas Pipelines segment related to the sale of three of our wholly owned interstate natural gas pipeline systems to DT Midstream, Inc.

Year Ended December 31, 2024 Total Segments Other and Eliminations Total

(Millions of dollars)

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Residue natural gas sales 1,340 ( 10 ) 1,330

Gathering, processing and exchange services revenue 696 — 696

Exchange services and natural gas gathering and processing revenue 760 — 760

Transportation and storage revenue 3,043 ( 23 ) 3,020

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Capital expenditures $ 1,953 $ 68 $ 2,021

(a) - Substantially all of our revenues relate to contracts with customers.

Year Ended Dec.

31, 2022 Natural Gas

Gathering and

Processing Natural Gas

Liquids Natural Gas

Pipelines Total

(a) - Substantially all of our revenues are related to contracts with customers.

Table of C ontents

Year Ended December 31, 2023 Natural Gas Gathering and Processing Natural Gas Liquids Natural Gas Pipelines Refined Products and Crude Total Segments

(Millions of dollars)

NGL and condensate sales $ 3,690 $ 18,329 $ — $ 22,019

Liquids commodity sales $ 2,479 $ 13,666 $ — $ 502 $ 16,647

Residue natural gas sales 1,398 — 39 — 1,437

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Cost of sales and fuel (exclusive of depreciation and operating costs) ( 2,364 ) ( 11,592 ) ( 28 ) ( 450 ) ( 14,434 )

( 5,117 ) ( 16,546 ) ( 25 ) ( 21,688 )

Operating costs ( 467 ) ( 666 ) ( 202 ) ( 198 ) ( 1,533 )

Equity in net earnings from investments 5 35 108 148

Adjusted EBITDA from unconsolidated affiliates 1 67 160 36 264

Noncash compensation expense 19 29 8 6 62

Other 2 88 — 90

Other (b) ( 1 ) 778 ( 2 ) — 775

Segment adjusted EBITDA $ 1,244 $ 3,045 $ 559 $ 465 $ 5,313

$ 1,037 $ 2,095 $ 488 $ 3,620

Depreciation and amortization $ ( 272 ) $ ( 334 ) $ ( 67 ) $ ( 92 ) $ ( 765 )

Equity in net earnings from investments $ ( 2 ) $ 58 $ 118 $ 28 $ 202

Investments in unconsolidated affiliates $ 24 $ 419 $ 526 $ 903 $ 1,872

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(a) - Intersegment revenues are primarily from commodity sales, which are based on the contracted selling price that is generally index-based and settled monthly.

Intersegment revenues for the Natural Gas Gathering and Processing segment totaled $ 3.7 billion and were not material for the Natural Gas Liquids and Natural Gas Pipelines segments.

Year Ended Dec.

31, 2022 Total

Segments Other and

Eliminations Total

(b) - Included a settlement gain of $ 779 million for the Natural Gas Liquids segment related to the Medford incident.

Year Ended December 31, 2023 Total Segments Other and Eliminations Total

(Millions of dollars)

Reconciliations of total segments to consolidated

NGL and condensate sales $ 22,019 $ ( 3,759 ) $ 18,260

Liquids commodity sales $ 16,647 $ ( 2,480 ) $ 14,167

Residue natural gas sales 1,437 — 1,437

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Capital expenditures $ 1,546 $ 49 $ 1,595

(a) - Substantially all of our revenues relate to contracts with customers.

Years Ended Dec.

(a) - Substantially all of our revenues are related to contracts with customers.

Table of C ontents

Years Ended December 31,

2025 2024 2023

Reconciliation of net income to total segment adjusted EBITDA

( Millions of dollars )

Net income $ 3,112 $ 2,659 $ 1,722

Reconciliation of income before income taxes to total segment adjusted EBITDA (Millions of dollars)

Income before income taxes $ 4,490 $ 4,110 $ 3,497

Interest expense, net of capitalized interest 1,783 1,371 866

Depreciation and amortization 1,514 1,134 769

Income taxes 998 838 528

Adjusted EBITDA from unconsolidated affiliates (a)

Equity in net earnings from investments (a)

( 439 ) ( 202 ) —

Noncash compensation expense and other 76 49 68

Other corporate costs (b) 35 70 —

Total segment adjusted EBITDA (a)(c)(d)

$ 6,819 $ 5,313 $ 3,620

(a) - Beginning in 2023, we updated our calculation methodology of adjusted EBITDA to include adjusted EBITDA from our unconsolidated affiliates using the same recognition and measurement methods used to record equity in net earnings from investments.

In prior periods, our calculation included equity in net earnings from investments.

This change resulted in an additional $ 62 million of adjusted EBITDA in 2023, and we have not restated prior periods.

(b) - The year ended Dec.

31, 2024, includes transaction costs related primarily to the EnLink Acquisitions and Medallion Acquisition of $ 73 million, offset partially by interest income of $ 39 million.

The year ended Dec.

31, 2023, includes transaction costs related to the Magellan Acquisition of $ 158 million, offset partially by interest income of $ 49 million and corporate net gains of $ 41 million on extinguishment of debt related to open market repurchases.

31, 2023, includes $ 633 million related to the Medford incident, including a settlement gain of $ 779 million, offset partially by $ 146 million of third-party fractionation costs.

(d) - The year ended Dec.

31, 2024, includes a gain of $ 227 million from the interstate natural gas pipeline divestiture.

Adjusted EBITDA from unconsolidated affiliates

Equity in net earnings from investments ( 386 ) ( 439 ) ( 202 )

Noncash compensation expense and other (a) 103 76 49

Corporate other (b) ( 65 ) 35 70

Total segment adjusted EBITDA (c)(d) $ 7,955 $ 6,819 $ 5,313

(a) - The year ended December 31, 2025, included noncash transaction costs related primarily to the EnLink Acquisition of $ 16 million included within noncash compensation expense and other.

(b) - The year ended December 31, 2025, included corporate net gains on extinguishment of debt of $ 106 million in connection with open market repurchases and interest income of $ 33 million, offset partially by transaction costs related primarily to the EnLink Acquisition of $ 65 million.

The year ended December 31, 2024, included transaction costs related primarily to the EnLink Acquisitions and Medallion Acquisition of $ 73 million, offset partially by interest income of $ 39 million.

The year ended December 31, 2023, included transaction costs related to the Magellan Acquisition of $ 158 million, offset partially by interest income of $ 49 million and corporate net gains on extinguishment of debt of $ 41 million in connection with open market repurchases.

(c) - The year ended December 31, 2024, included a gain of $ 227 million from the interstate natural gas pipeline divestiture.

(d) - The year ended December 31, 2023, included $ 633 million related to the Medford incident, including a settlement gain of $ 779 million, offset partially by $ 146 million of third-party fractionation costs.

CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 8. Financial Statements and Supplementary Data