What changed in this filing

/stocks — the workspaceLOADING

Item 1. Business

2025-02-18 compared with 2024-02-29 · 97 added, 143 removed, 373 unchanged (39% of the section changed)

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• Ameren Missouri operates a rate-regulated electric generation, transmission, and distribution business and a rate-regulated natural gas distribution business in Missouri.

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• Ameren Illinois operates rate-regulated electric transmission, electric distribution, and natural gas distribution businesses in Illinois.

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An illustration of the Ameren Companies’ reporting structures is provided below:

(a) The Ameren Transmission segment also includes allocated Ameren (parent) interest charges, as well as other subsidiaries engaged in electric transmission project development and investment.

(a) Ameren Missouri consolidates AMF, which is wholly owned by Ameren Missouri.

(b) The Ameren Transmission segment also includes allocated Ameren (parent) interest charges, as well as other subsidiaries engaged in electric transmission project development and investment.

RATES AND REGULATION

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The extent of the regulatory lag varies for each of Ameren’s electric and natural gas jurisdictions, with the Ameren Transmission business experiencing the least amount of regulatory lag.

Depending on the

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jurisdiction, the effects of regulatory lag are mitigated by various means, including annual revenue requirement reconciliations, the decoupling of revenues from sales volumes to ensure revenues approved in a regulatory rate review are not affected by changes in sales volumes, the recovery of certain capital investments between traditional regulatory rate reviews, the level and timing of expenditures, the use of future test years to establish customer rates, and the use of trackers and riders.

Depending on the jurisdiction, the effects of regulatory lag are mitigated by various means, including annual revenue requirement reconciliations, the decoupling of revenues from sales volumes to ensure revenues approved in a regulatory rate review are not affected by changes in sales volumes, the recovery of certain capital investments between traditional regulatory rate reviews, the level and timing of expenditures, the use of future test years to establish customer rates, and the use of trackers and riders.

The MoPSC regulates rates and other matters for Ameren Missouri.

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The FERC regulates Ameren Missouri’s, Ameren Illinois’, and ATXI’s cost-based rates for the wholesale transmission and distribution of energy in interstate commerce and various other matters discussed below under General Regulatory Matters.

The following table summarizes the key terms of the rate orders in effect for customer billings for each of Ameren’s rate-regulated utilities as of January 1, 2024, except as noted:

The following table summarizes the key terms of the rate orders in effect for customer billings for each of Ameren’s utilities as of January 1, 2025, except as noted:

Rate Regulator Effective

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Electric distribution delivery service (e)

ICC December 2023 January 2024 8.72% 50.00% $3.9 29%

ICC December 2024 (e) 8.72% 50.00% (e) 27%

Natural gas delivery service (f)

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(d) This rate order did not specify an ROE or a capital structure.

(e) In December 2023, the ICC issued an order in Ameren Illinois' MYRP proceeding, approving base rates for electric distribution services for 2024 through 2027.

This rate order was based on forecasted recoverable costs and an ICC-determined ROE applied to Ameren Illinois’ 2022 year-end rate base approved by the 2022 electric distribution service revenue requirement reconciliation adjustment order.

The December 2023 ICC order rejected Ameren Illinois’ Grid Plan, which was addressed as part of the MYRP proceeding.

The ICC concluded that the proposed Grid Plan did not meet certain statutory requirements and directed Ameren Illinois to file a revised Grid Plan within three months.

Ameren Illinois expects to file a revised Grid Plan with the ICC in March 2024, and also expects to file a request to update the associated MYRP revenue requirements for 2024 through 2027 in the first half of 2024.

The ICC will be under no deadline to act on the revised Grid Plan when filed.

This rate base will remain in effect through 2027, unless the rehearing of the MYRP order or approval of a revised Grid Plan by the ICC results in an update of each year’s revenue requirement.

(e) In December 2024, the ICC issued an order in Ameren Illinois’ MYRP proceeding.

The order approved an average annual rate base for 2024, 2025, 2026, and 2027 of $4.2 billion, $4.4 billion, $4.6 billion, and $4.8 billion, respectively.

Rate changes consistent with the December 2024 order became effective in late December 2024.

Under an MYRP, Ameren Illinois will reconcile its actual revenue requirement, as adjusted for certain cost variations, to ICC-approved electric distribution service rates on an annual basis, subject to a reconciliation cap.

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They are determined by a company-specific, forward-looking formula ratemaking framework based on each year’s forecasted information.

The 10.52% return, which includes a 50-basis-point incentive adder for participation in an RTO, is based on the FERC’s May 2020 order.

The 10.48% return, which includes a 50-basis-point incentive adder for participation in an RTO, is based on the FERC’s October 2024 order.

For additional information on Ameren Missouri, Ameren Illinois, and ATXI rate matters, see Results of Operations and Outlook in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, Quantitative and Qualitative Disclosures About Market Risk under Part II, Item 7A, and Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

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Ameren Missouri, Ameren Illinois, and ATXI are members of the SERC.

The SERC is one of six regional entities and represents all or portions of 16 central and southeastern states under authority from the NERC for the purpose of

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implementing and enforcing reliability standards approved by the FERC.

The SERC is one of six regional entities and represents all or portions of 16 central and southeastern states under authority from the NERC for the purpose of implementing and enforcing reliability standards approved by the FERC.

Ameren Missouri is also a member of the MRO, which is also one of the six regional entities and represents all or portions of 16 central, southern, and midwestern states, as well as two Canadian provinces, under authority from the NERC.

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The licenses for the Osage Energy Center and the Taum Sauk Energy Center expire in 2047 and 2044, respectively.

Ameren Missouri’s Keokuk Energy Center and its dam on the Mississippi River between Hamilton, Illinois, and Keokuk, Iowa, are operated under authority granted by an Act of Congress in 1905.

Ameren Missouri’s Keokuk Energy Center and its dam on the Mississippi River between Hamilton, Illinois, and Keokuk, Iowa,

are operated under authority granted by an Act of Congress in 1905.

The Keokuk Energy Center dam safety program is regulated by the Illinois Department of Natural Resources.

For additional information on regulatory matters, see Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

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Our electric generation, transmission, and distribution and natural gas distribution and storage operations must comply with a variety of statutes and regulations relating to the protection of the environment and human health and safety.

These environmental statutes and regulations are comprehensive and include the storage, handling, and disposal of waste materials and hazardous substances, emergency planning and response requirements, limitations and standards applicable to discharges from our facilities into the air or water that are enforced through permitting requirements, and wildlife protection laws, including those related to endangered species.

Federal and state authorities continually revise these regulations and adopt new regulations, which may impact our planning process and the ultimate implementation of these or other new or revised regulations.

Local and state land use requirements can also potentially impact our planning activities.

For discussion of environmental matters, including NO x and SO 2 emission reduction requirements, regulation of CO 2 emissions, wastewater discharge standards, remediation efforts, CCR management regulations, and a discussion of litigation against Ameren Missouri with respect to NSR, the Clean Air Act, and Missouri law in connection with projects at Ameren Missouri’s Rush Island Energy Center, see Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

These environmental statutes and regulations are comprehensive and include the storage, handling, and disposal of waste materials and hazardous substances, emergency planning and response requirements, limitations and standards applicable to discharges from our facilities into the air or water that are enforced through permitting requirements, and natural resource protection laws, including those related to endangered species.

Federal and state authorities periodically review and modify existing regulations and adopt new regulations, which may impact our planning process and the ultimate implementation of these or other new or revised regulations.

Recent and potential new executive orders issued by the current federal administration as well as local and state land use requirements can also impact our planning activities.

For discussion of environmental matters, including NO x and SO 2 emission reduction requirements, regulation of CO 2 emissions, wastewater discharge standards, remediation efforts, and CCR management regulations, and a discussion of litigation against Ameren Missouri with respect to NSR, the Clean Air Act, and Missouri law in connection with projects at Ameren Missouri’s Rush Island Energy Center, see Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

Ameren owns an integrated transmission system that is composed of the transmission assets of Ameren Missouri, Ameren Illinois, and ATXI.

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The AMMO balancing authority area includes the load and most energy centers of Ameren Missouri, and had a peak demand of 7,560 MWs in 2024.

The AMIL balancing authority area includes the load of Ameren Illinois and certain natural gas-fired energy centers of Ameren Missouri, and had a peak demand of 8,859 MWs in 2023.

The AMIL balancing authority area includes the load of Ameren Illinois and certain Ameren Missouri energy centers located in Illinois, and had a peak demand of 8,479 MWs in 2024.

The Ameren transmission system directly connects with 15 other balancing authority areas for the exchange of electric energy.

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Ameren Illinois’ election to participate in the MISO is subject to the ICC’s oversight.

In July 2022, the ICC issued an order requiring Ameren Illinois to perform a cost-benefit study of continued participation in the MISO compared to participation in PJM Interconnection LLC, another RTO.

In July 2023, Ameren Illinois filed its cost-benefit study with the ICC.

The study concluded that continued participation in the MISO was prudent and more cost-beneficial than participation in PJM Interconnection LLC.

In January 2024, the ICC staff submitted a report recommending the ICC not take any action with regard to changing Ameren Illinois’ RTO membership.

The ICC is under no obligation to issue an order related to the cost-benefit study.

For additional information regarding the RTO cost-benefit study, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

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SUPPLY OF ELECTRIC POWER

Ameren Missouri sells nearly all of its capacity to the MISO and purchases the capacity it needs to supply its native load sales from the MISO.

In the April 2023 MISO capacity auction, Ameren Missouri’s generation resources exceeded its native load capacity requirements for the June 2023 through May 2024 period.

Ameren Missouri sells all of its capacity to the MISO and purchases the capacity it needs to supply its native load sales from the MISO.

Ameren Illinois purchases capacity from the MISO and through bilateral contracts resulting from IPA procurement events.

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Factors that could cause Ameren Missouri to purchase power include, among other things, energy center outages, the fulfillment of renewable energy requirements, extreme weather conditions, the availability of power at a cost lower than its generation cost, and the lack of sufficient owned generation availability.

Ameren Missouri files a long-term nonbinding integrated resource plan with the MoPSC every three years.

The most recent integrated resource plan was filed in September 2023 and includes Ameren Missouri’s preferred plan for meeting customers’ projected long-term energy needs in a manner that maintains system reliability and customer affordability while transitioning to clean energy generation in an environmentally responsible manner.

The preferred plan includes, among other things, the following:

• adding an 800-MW natural gas-fired simple-cycle energy center by 2027 and an additional 1,200-MW natural gas-fired combined-cycle energy center by 2033, representing investment opportunities of $0.8 billion and $1.7 billion, respectively;

• adding 2,800 MWs of renewable generation by 2030, which includes the 900 MWs of solar generation projects discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report, and an additional 1,900 MWs by 2036, representing investment opportunities of $5.3 billion and $4.1 billion, respectively;

• adding 400 MWs of battery storage by 2030 and an additional 400 MWs by 2035, representing investment opportunities of $0.6 billion and $0.7 billion, respectively;

• adding 1,200 MWs of other clean dispatchable generation resources by 2040 and an additional 1,200 MWs by 2043;

Ameren Missouri files a long-term nonbinding preferred resource plan with the MoPSC every three years.

The most recent preferred resource plan was filed in September 2023.

Ameren Missouri expects to file a notice of change in its preferred resource plan with the MoPSC in February 2025 to address new load growth opportunities resulting from entities in various industries, including data center and manufacturing, that are considering either locating or expanding their operations within Ameren Missouri’s service territory.

The 2025 Change to the 2023 PRP is expected to include, among other things, the following:

• adding 1,600 MWs of natural gas-fired simple-cycle generation by 2030, which includes the 800-MW Castle Bluff Natural Gas Project discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report, and an additional 1,200 MWs by 2043;

• adding 2,100 MWs of natural gas-fired combined-cycle generation by 2035 and an additional 1,200 MWs by 2040;

• adding 3,200 MWs of renewable generation by 2030, which includes the 900 MWs of solar generation projects discussed in Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report, and an additional 1,500 MWs by 2035;

• adding 1,000 MWs of battery storage by 2030 and an additional 800 MWs by 2042;

• adding 1,500 MWs of nuclear generation by 2040;

• retiring all of Ameren Missouri’s coal-fired energy centers by 2042;

• accelerating the retirement date of the Rush Island coal-fired energy center from 2025 to 2024;

• extending the retirement date of the Sioux coal-fired energy center from 2030 to 2032 to ensure reliability during the transition to clean energy generation, which is subject to the approval of a change in depreciable lives of the energy center’s assets by the MoPSC;

• retiring 1,800 MWs of Ameren Missouri’s natural gas-fired energy centers by 2040 to comply with Illinois law;

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• the expectation that Ameren Missouri will seek and receive NRC approval for an extension of the operating license for the Callaway Energy Center beyond its current 2044 expiration date.

The addition of renewable or natural gas-fired generation facilities is subject to obtaining necessary project approvals, including FERC approval and the issuance of a CCN by the MoPSC, as applicable.

The addition of renewable, natural gas-fired, or nuclear generation facilities is subject to obtaining necessary project approvals, including FERC approval and the issuance of a CCN by the MoPSC, as applicable.

Ameren Missouri would be adversely affected if the MoPSC does not allow recovery of the remaining investment and decommissioning costs associated with the retirement of an energy center, as well as the ability to earn a return on that remaining investment and those decommissioning costs.

In connection with the accelerated retirement of the Rush Island Energy Center, Ameren Missouri is seeking approval from the MoPSC to finance the costs associated with the retirement, including the remaining unrecovered net plant balance associated with the facility, through the issuance of securitized utility tariff bonds pursuant to the Missouri securitization statute.

The next integrated resource plan is expected to be filed in September 2026.

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The next preferred resource plan is required to be filed by October 2026.

Ameren Missouri continues to evaluate its longer-term needs for new generating capacity.

The need for investment in new sources of energy is dependent on several key factors, including continuation of and customer participation in energy-efficiency programs, the amount of distributed generation from customers, load growth, technological advancements, costs of generation alternatives, environmental regulation of coal-fired and natural gas-fired power plants, and state renewable energy requirements, which could lead to the retirement of current baseload assets before the end of their current useful lives or alterations in the way those assets operate, which could result in increased capital expenditures and/or increased operations and maintenance expenses.

The need for investment in new sources of energy is dependent on several key factors, including continuation of and customer participation in energy-efficiency programs, the amount of distributed generation from customers, load growth, including demand from data centers, technological advancements, costs of generation alternatives, environmental regulation of coal-fired and natural gas-fired power plants, changes in United States energy policy and priorities under the current federal administration, and state renewable energy requirements, which could lead to the retirement of current baseload assets before the end of their current useful lives or alterations in the way those assets operate, which could result in increased capital expenditures and/or increased operations and maintenance expenses.

Because of the significant time required to plan, acquire permits for, and build a baseload energy center, Ameren Missouri continues to study alternatives and to take steps to preserve options to meet future demand.

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Missouri law required Ameren Missouri to offer solar rebates through December 2023 and currently requires Ameren Missouri to offer net metering to certain customers that install renewable generation at their premises.

The difference between the cost of the solar rebates and the amount set in base rates was deferred as a regulatory asset or liability under the RESRAM, and earn carrying costs at short-term interest rates.

The difference between the cost of the solar rebates and the amount set in base rates was deferred as a regulatory asset or liability under the RESRAM, and earns carrying costs at short-term interest rates.

Customers that elect to enroll in net metering are allowed to net their generation against their distribution usage within each billing month.

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Pursuant to the CEJA, Ameren Illinois is required to file a Grid Plan with the ICC every four years.

Ameren Illinois expects to file a revised Grid Plan with the ICC in March 2024 after its initial Grid Plan for the years 2023 to 2027 was rejected by the ICC’s December 2023 order in Ameren Illinois’ MYRP proceeding.

In December 2024, the ICC issued an order approving Ameren Illinois’ revised Grid Plan under its MYRP proceeding for electric distribution service for 2024 through 2027.

For additional information regarding Ameren Illinois’ MYRP proceeding, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.

The Grid Plan outlines how Ameren Illinois expects to invest in electric distribution infrastructure in order to support grid modernization, clean energy, energy efficiency, and the state of Illinois’ renewable energy, equity, climate, electrification, and environmental goals.

Ameren Illinois’ next Grid Plan is required to be filed by mid-January 2026.

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POWER GENERATION

Ameren Missouri owns energy centers that rely on a diverse fuel portfolio, including coal, nuclear, and natural gas, as well as renewable sources of generation, which include hydroelectric, wind, methane gas, and solar.

All of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978.

Ameren Missouri owns energy centers that rely on a diverse fuel portfolio, including coal, nuclear, and natural gas, as well as renewable sources of generation.

Both of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978.

As of December 31, 2024, Ameren Missouri’s coal-fired energy centers represented 6% and 11% of Ameren’s and Ameren Missouri’s rate base, respectively.

The Callaway Energy Center began operation in 1984 and is licensed to operate until 2044.

Ameren Illinois operates a solar generation facility, which is one of two pilot solar projects Ameren Illinois is allowed to invest in under the CEJA.

The second solar generation facility is planned be placed in service before the end of 2025.

Ameren Illinois operates two solar generation facilities, which are two of three pilot solar projects Ameren Illinois is allowed to invest in under the CEJA.

The third solar generation facility is planned to be placed in service before the end of 2026.

See Item 2 – Properties under Part I of this report for information regarding our energy centers.

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Ameren Missouri has an ongoing need for coal as fuel for generation, and pursues a price-hedging strategy consistent with this requirement.

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Deliveries from the Powder River Basin have occasionally been restricted because of rail congestion, staffing and equipment issues, infrastructure maintenance, derailments, weather, and supplier financial hardship.

Delays and disruptions in coal deliveries could cause Ameren Missouri to pursue a strategy that could include reducing off-system sales of power during low-margin periods, buying higher-cost fuels to generate required electricity, and purchasing power from other sources.

Delays and disruptions in coal deliveries could cause Ameren Missouri to pursue a strategy that could include reducing off-system sales of power during low-earning periods, buying higher-cost fuels to generate required electricity, and purchasing power from other sources.

The production of nuclear fuel involves the mining and milling of uranium ore to produce uranium concentrates, the conversion of uranium concentrates to uranium hexafluoride gas, the enrichment of that gas, the conversion of the enriched uranium hexafluoride gas into uranium dioxide fuel pellets, and the fabrication into fuel assemblies.

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Ameren Missouri has inventories and supply contracts sufficient to meet all of its uranium (concentrate and hexafluoride), conversion, enrichment, and fabrication requirements at least through the spring 2028 refueling.

Ameren Missouri operates several renewable energy centers, which includes hydroelectric, wind, methane gas, and solar energy centers.

The High Prairie and Atchison energy centers are wind generation facilities.

The Huck Finn, Boomtown, and Cass County energy centers are solar generation facilities.

The Osage and Keokuk energy centers generate electricity using hydroelectric dams located on the Lake of the Ozarks and the Mississippi River, respectively.

The Maryland Heights Energy Center generates electricity by burning methane gas collected from a landfill.

RENEWABLE ENERGY AND ZERO EMISSION STANDARDS

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For renewable generation facilities located in Missouri, 125% of the electricity generated counts towards meeting the requirement.

Ameren Missouri expects to satisfy the non-solar requirement in 2024 with its High Prairie Renewable, Atchison Renewable, Keokuk, and Maryland Heights energy centers, a 102-MW power purchase agreement with a wind farm operator, which expires in August 2024, and previously purchased renewable energy credits.

The High Prairie Renewable and Atchison Renewable energy centers are wind generation facilities.

The Keokuk Energy Center generates electricity using a hydroelectric dam located on the Mississippi River.

The Maryland Heights Energy Center generates electricity by burning methane gas collected from a landfill.

Ameren Missouri is meeting the solar energy requirement by purchasing solar-generated renewable energy credits from customer-installed systems and by generating energy at its solar facilities.

Ameren Missouri expects to satisfy the requirement in 2025 with its High Prairie, Atchison, Huck Finn, Keokuk, Maryland Heights, and other solar energy centers, along with other renewable energy credits purchased by Ameren Missouri, including solar-generated renewable energy credits purchased from customer-installed systems.

Ameren Illinois

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Ameren Illinois has also entered into contracts, ending in 2032, to purchase approximately 0.6 million wind renewable energy credits per year.

Pursuant to the CEJA, if funds collected from customers are not used to procure renewable energy credits, they would be refunded to customers pursuant to a reconciliation proceeding, the first of which was initiated in August 2023.

Based on amounts collected from customers and renewable energy credit purchases under contract, the August 2023 reconciliation proceeding did not result in refunds to customers.

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Pursuant to the CEJA, if funds collected from customers are not used to procure renewable energy credits, they would be refunded to customers pursuant to an annual reconciliation proceeding, the first of which was approved by the ICC in January 2025, which was the June 2017 through May 2018 reconciliation period, and did not result in refunds to customers.

Based on amounts collected from customers and obligations under the program, the June 2018 through May 2019 reconciliation period is not expected to result in refunds to customers, pending review by the ICC.

Illinois law also required Ameren Illinois to enter into contracts to purchase zero emission credits in an amount equal to approximately 16% of the actual amount of electricity delivered to retail customers during calendar year 2014, pursuant to Illinois’ zero emission standard.

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As a component of the energy-efficiency programs, Ameren Missouri and Ameren Illinois have invested in electric smart meters to provide customers more visibility to their energy consumption and facilitate more efficient use of energy.

As of December 31, 2023, smart meters have been installed for 88% of Ameren Missouri’s electric customers.

Ameren Illinois has completed its transition to smart meters, which have been installed for nearly all its electric and natural gas customers.

As of December 31, 2024, Ameren Missouri and Ameren Illinois have completed the transition to smart meters, which have been installed for nearly all electric and natural gas customers.

Ameren Missouri

In Missouri, the Missouri Energy Efficiency Investment Act established a rider that, among other things, allows electric utilities to recover costs with respect to MoPSC-approved customer energy-efficiency programs.

The law requires the MoPSC to ensure that a utility’s financial incentives are aligned to help customers use energy more efficiently, to provide timely cost recovery, and to provide earnings opportunities associated with cost-effective energy-efficiency programs.

Missouri does not have a law mandating energy-efficiency programs.

In 2018, the MoPSC issued an order approving Ameren Missouri’s MEEIA 2019 plan.

The plan includes a portfolio of customer energy-efficiency and demand response programs through December 2024.

Ameren Missouri intends to invest approximately $420 million over the life of the plan, including $76 million in 2024.

In addition, the plan includes a performance incentive that provides Ameren Missouri an opportunity to earn revenues by achieving certain customer energy-efficiency goals.

If the target program spending goal is achieved for 2024, the performance incentive would result in revenues of $12 million in 2024.

Through 2023, Ameren Missouri has invested approximately $343 million in MEEIA 2019 customer energy-efficiency programs.

Additionally, as part of its Smart Energy Plan, Ameren Missouri has invested $336 million in smart meters since 2019.

The MEEIA rider allows Ameren Missouri to collect from, or refund to, customers any difference between actual program costs, lost electric margins, and any performance incentive and the amounts collected from customers, without a traditional regulatory rate review, subject to MoPSC prudence reviews, until lower volumes resulting from the MEEIA programs are reflected in base rates.

Customer rates, based upon both forecasted program costs and lost electric margins and collected via the MEEIA rider, are reconciled annually to actual results.

Missouri does not have a law mandating energy-efficiency or demand response programs.

In November 2024, the MoPSC issued an order approving a nonunanimous stipulation and agreement for Ameren Missouri’s MEEIA 2025 plan, which includes a portfolio of customer energy-efficiency and demand response programs, along with the continued use of the MEEIA rider.

Ameren Missouri intends to invest $51 million annually in 2025 and 2026 and $22 million in 2027 for customer energy-efficiency and demand response programs.

In addition, the order approved performance incentives applicable to each plan year to earn revenues by achieving certain spending and demand response goals.

If 100% of the goals are achieved in 2025, 2026, and 2027, Ameren Missouri would earn performance incentive revenues of $5 million, $5 million, and $2 million, respectively.

Through 2024, Ameren Missouri has invested approximately $415 million in MEEIA 2019 customer energy-efficiency and demand response programs.

The MEEIA rider allows Ameren Missouri to collect from customers its actual program costs, lost electric revenues, and any performance incentive, without a traditional regulatory rate review, subject to MoPSC prudence reviews, until lower volumes resulting from

the MEEIA programs are reflected in base rates.

Customer rates, based upon both forecasted program costs and lost electric revenues and collected via the MEEIA rider, are reconciled annually to actual results.

Ameren Illinois

Illinois law requires Ameren Illinois to offer customer energy-efficiency programs, and imposes electric energy-efficiency savings goals and a maximum annual amount of investment in electric energy-efficiency programs, which is approximately $120 million annually through 2029 and may increase by up to approximately $30 million from 2026 to 2029 depending on the election of certain customers to participate in the programs.

Pursuant to Illinois law, Ameren Illinois offers customer energy-efficiency programs, and is subject to electric energy-efficiency savings goals and a maximum annual amount of investment in electric energy-efficiency programs.

Ameren Illinois’ planned investments in electric energy-efficiency programs is approximately $120 million in 2025 and approximately $125 million annually from 2026 to 2029.

Every four years, Ameren Illinois is required to file a four-year electric energy-efficiency plan with the ICC.

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The order authorized electric and natural gas energy-efficiency program expenditures of $476 million and $66 million, respectively, over the four-year period.

Ameren Illinois is required to file an updated four-year electric energy-efficiency plan with the ICC by March 2025.

Illinois law allows Ameren Illinois to earn a return on its electric energy-efficiency program investments.

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Ameren Illinois’ natural gas energy-efficiency program costs are recovered through a rider.

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NATURAL GAS SUPPLY FOR DISTRIBUTION

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Ameren Missouri and Ameren Illinois each develop and manage a portfolio of natural gas supply resources.

These resources include firm natural gas supply agreements with producers, firm interstate and intrastate transportation capacity, firm no-notice storage capacity leased from interstate pipelines, and on-system storage facilities to maintain natural gas deliveries to customers throughout the year and especially during peak demand periods.

These resources include firm natural gas supply agreements, firm interstate and intrastate transportation capacity, firm no-notice storage capacity leased from interstate pipelines, and on-system storage facilities to maintain natural gas deliveries to customers throughout the year and especially during peak demand periods.

Ameren Missouri and Ameren Illinois primarily use Panhandle Eastern Pipe Line Company, Trunkline Gas Company, Natural Gas Pipeline Company of America, Mississippi River Transmission Corporation, Northern Border Pipeline Company, MoGas Pipeline, and Texas Eastern Transmission Corporation interstate pipeline systems to transport natural gas to their systems.

In addition to transactions requiring physical delivery, certain financial instruments, including those entered into in the New York Mercantile Exchange futures market and in the over-the-counter financial markets, are used to hedge the price paid for natural gas.

In addition to transactions requiring physical delivery, certain financial instruments, including those entered into in the over-the-counter financial markets, are used to hedge the price paid for natural gas.

Natural gas supply costs are passed on to customers of Ameren Missouri and Ameren Illinois under PGA clauses, subject to prudence reviews by the MoPSC and the ICC.

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The execution of Ameren’s core strategy to invest in rate-regulated energy infrastructure, enhance regulatory frameworks and advocate for responsible policies, and optimize operating performance to capitalize on opportunities to benefit our customers, communities, shareholders, and the environment is driven by the capabilities and engagement of our workforce.

Ameren’s workforce strategy is designed to promote a skilled and diverse workforce that is prepared to deliver on Ameren’s mission ( To Power the Quality of Life ) and vision ( Leading the Way to a Sustainable Energy Future ), both today and in the future.

Ameren’s workforce strategy is designed to promote a skilled workforce that is well-prepared to deliver on Ameren’s mission ( To Power the Quality of Life ) and vision ( Leading the Way to a Sustainable Energy Future ), both today and in the future.

Our workforce strategy is anchored in four key pillars:

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Ameren’s chief executive officer and chief human resources officer, with the support of other leaders of the Ameren Companies, are responsible for developing and executing our workforce strategy.

In addition to reviewing and determining the Ameren Companies’ compensation practices and policies for the chief executive officer and other executive officers, the Human Resources Committee of Ameren’s board of directors is responsible for oversight of Ameren’s human capital management practices and policies, including those related to diversity, equity, and inclusion.

In addition to reviewing and determining the Ameren Companies’

compensation practices and policies for the chief executive officer and other executive officers, the Human Resources Committee of Ameren’s board of directors is responsible for oversight of Ameren’s human capital management practices and policies.

The Human Resources Committee and Ameren’s board of directors are updated regularly on human capital matters.

We strive to cultivate a mission-driven, values-based culture that enables the sustainable execution of our core strategy.

We design our human capital management practices and policies to reinforce our core values, shape our culture, and drive employee engagement.

We design our human capital management practices and policies to reinforce our values, shape our culture, and drive employee engagement.

In doing so, we strive to align our employees to our mission and vision, improve safety, continuously improve operating performance, attract and retain top talent, and recognize employee contributions, among other things.

We assess employee engagement through a variety of channels.

As a part of our assessment, we conduct confidential employee engagement surveys twice each year to identify areas of strength and opportunities for improvement in our employees’ experience, and take actions aimed at increasing employee engagement.

As a part of our assessment, we conduct confidential employee engagement surveys to identify areas of strength and opportunities for improvement in our employees’ experience, and take actions aimed at increasing employee engagement.

We also offer flexible work arrangements, such as permitting certain employees to work from alternate locations or to make adjustments to an employee’s daily work hours, among other things, complemented by our work to advance the digital enablement of our workforce, and have enhanced our facilities and workforce policies and practices to increase collaboration and productivity.

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In addition to comprehensive safety and security standards, and mandatory health, safety, and security training programs for applicable employees, we promote programs designed to encourage employees to provide feedback on practices or actions that could harm employees, customers, or the Ameren Companies, including perceived issues related to safety, security (both physical and cyber), ethics and compliance violations, or acts of discrimination.

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We seek to foster diversity, equity, and inclusion across our organization.

Our efforts extend to the community through philanthropic contributions and volunteerism, including to support non-profit organizations in leading community-building efforts, providing education and support to our community and company leaders through our diversity leadership summit, providing various training programs, and organizing and promoting opportunities for employee volunteerism.

We also have employee resource groups, which bring together groups of employees who share common interests or backgrounds.

Within these groups, employees collaborate to address concerns and provide training and development opportunities, among other things.

Ameren’s leaders play a critical role in setting and executing Ameren’s strategic initiatives, modeling our values and culture, and engaging and enabling the workforce.

As such, we seek to develop a strong, diverse leadership team.

As such, we seek to develop a strong leadership team with a variety of experiences and perspectives.

Management engages in an extensive succession planning process annually, which includes the involvement of Ameren’s board of directors.

We develop our leaders both individually, through job rotations, work experiences, and leadership development programs, and as a team, through collaborative learning and mentoring relationships.

Throughout the year, we offer a variety of forums intended to connect our leaders to our mission, values, strategy and culture, build leadership skills and capabilities, and to promote connection and inclusion.

We develop our leaders both individually, through job rotations, mentoring and sponsorships, work experiences, and leadership development programs, and as a team.

Throughout the year, we offer a variety of forums intended to connect our leaders to our mission, values, strategy and culture, and build leadership skills and capabilities.

In addition, we evaluate our organizational structure and make adjustments and expand roles to facilitate execution of our strategy and organizational efficiency.

In order to attract and retain a skilled and diverse workforce, we promote an inclusive work environment, provide opportunities for employees to expand their knowledge and skill sets, and support career development.

Our talent management initiatives include a wide range of recruiting partnerships and programs, including those programs discussed below.

In order to attract and retain a skilled and highly qualified workforce, we provide opportunities for employees to expand their knowledge and skill sets, and we support their career development.

Our onboarding efforts are designed to ensure early engagement, including the opportunity to participate in mentoring programs.

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As our business needs change, we remain focused on ensuring that our workforce has the tools and skills necessary to deliver on our strategic initiatives.

We have established programs to recruit early and mid-career talent to further enhance the diversity of our workforce pipelines.

These programs include skilled craft education and training for individuals interested in skilled craft roles, an intern/co-op program that serves as a pipeline for STEM-related careers, a career reentry program for experienced professionals transitioning from voluntary career breaks, a program for individuals transitioning from military service, and an early career rotation program.

Additionally, each year management and the Human Resources Committee of Ameren’s board of directors review the diversity of our workforce, leadership team, and leadership pipeline.

Our talent management initiatives include a wide range of recruiting partnerships and programs, designed to engage a variety of career seekers.

We have established programs to recruit early and mid-career talent to further enhance our workforce pipelines.

These programs include skilled craft education and training for individuals interested in skilled craft roles, an intern/co-op program that serves as a pipeline for STEM-related careers, a program for individuals transitioning from military service, and an early career rotation program.

The majority of our workforce is comprised of skilled-craft and STEM-related professional and technical employees.

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The majority of employee attrition is attributable to employee retirements, generally allowing for thoughtful workforce and succession planning in advance of these planned transitions.

The following table presents our employee count and their average tenure at December 31, 2023, and the attrition rate in 2023:

The following table presents our employee count and their average tenure as of December 31, 2024, and the attrition rate in 2024:

Count Average Tenure

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Ameren Services 2,043 11 10%

Ameren’s workforce is diverse in many ways.

At the officer level, which represented 50 individuals as of December 31, 2023, 26% were female, and 26% were racially and/or ethnically diverse.

The following table presents our total employee population that is represented by a collective bargaining unit, is a female, or is racially and/or ethnically diverse at December 31, 2023:

Collective Bargaining Unit Female (a)

Racially and/or Ethnically Diverse (a)

Ameren 46% 24% 16%

Ameren Missouri 58% 17% 14%

Ameren Illinois 54% 23% 14%

Ameren Services 10% 41% 23%

(a) Gender, race, and ethnicity were self-reported by our employees.

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The following table presents Ameren’s employees by generation at December 31, 2023:

The following table presents Ameren’s employees by generation as of December 31, 2024:

Generation Description Ameren Ameren Missouri Ameren Illinois Ameren Services

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Collective bargaining units at Ameren’s subsidiaries consist of the International Brotherhood of Electrical Workers, the International Union of Operating Engineers, the Laborer’s International Union of North America, the United Association of Plumbers and Pipefitters, and the United Government Security Officers of America.

As of December 31, 2024, these labor unions collectively represented 46%, 59%, 55%, and 10% of the employees at Ameren, Ameren Missouri, Ameren Illinois, and Ameren Services, respectively.

The Ameren Companies expect continued constructive relationships with their respective labor unions.

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Further, we offer our employees various programs that encourage overall well-being, including wellness and employee assistance programs.

We strive to provide a competitive and sustainable rewards package that supports our ability to attract, engage, and retain a talented and diverse workforce, while at the same time reinforcing and rewarding strong performance.

We strive to provide a competitive and sustainable rewards package that supports our ability to attract, engage, and retain a talented and highly qualified workforce, while at the same time reinforcing and rewarding strong performance.

INDUSTRY ISSUES

We are facing issues common to the electric and natural gas utility industry.

We are facing issues common to the electric and natural gas utility industry, as well as new and emergent issues impacting the industry as a whole.

These issues include:

• the potential for changes in laws, regulations, enforcement efforts, and policies at the state and federal levels;

• corporate tax law changes, including the IRA, as well as additional interpretations, regulations, amendments, or technical corrections that affect the amount and timing of income tax payments, reduce or limit the ability to claim certain deductions and use carryforward tax benefits and/or credits, or result in rate base reductions;

• the potential for changes in laws, regulations, enforcement efforts, and policies at the federal, state, and international levels, including but not limited to, complex new and proposed environmental laws, such as air and water quality standards, mercury emissions standards, limitations on the use of natural gas in generation, CCR management requirements, and potential CO 2 limitations, which may limit, or result in the cessation of, the operation of electric generating units;

• corporate tax law changes, including the IRA, as well as additional interpretations, regulations, amendments, or technical corrections that affect the amount and timing of income tax payments or the transferability of production and investment tax credits, reduce or limit the ability to claim certain deductions and use carryforward tax benefits and/or credits, or result in rate base reductions;

• cybersecurity risks, cyber attacks, including ransomware and other ransom-based attacks and those attacks arising from or generated by artificial intelligence, hacking, social engineering, and other forms of malicious cybersecurity and/or privacy events, which could result in the loss of operational control of energy centers and electric and natural gas transmission and distribution systems and/or the theft or inappropriate release of certain types of information, including sensitive customer, employee, financial, and operating system information;

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• political, regulatory, and customer resistance to higher rates;

• the potential for more intense competition in generation, supply, and distribution, including new technologies and their declining costs;

• the impacts from new data centers expected to be constructed over the next several years, including increased competition among utilities, independent power producers and non-traditional market entrants, providing generation and resource adequacy to support the projected load growth, and managing the impact on customer rates;

• the impact and effectiveness of vegetation management programs;

• the potential for reliability issues due to inadequate resources resulting from the retirement of fossil-fuel-fired and nuclear generation facilities as they are replaced with renewable energy generation sources, market inefficiencies related to prices for purchased power, capacity, and ancillary services, and other factors;

• the potential for reliability issues due to inadequate resources resulting from the retirement of fossil-fuel-fired generation facilities as they are replaced with renewable energy generation sources, increasing load growth, and market inefficiencies related to prices for purchased power, capacity, and ancillary services, and other factors;

• the need to place new transmission and generation facilities in service, which is dependent upon timely regulatory approvals and the availability of necessary labor and materials, among other things, to maintain grid reliability;

• the modernization of the electric grid to accommodate a two-way flow of electricity and increase capacity for distributed generation interconnection;

• pressure and uncertainty on customer growth and sales volumes in light of increased competition in the industry and economic conditions;

• the ability to recover and earn a fair return on investments due to changes in the allowed ROE, including ROE incentive adders on FERC-regulated electric transmission assets;

• the influence of macroeconomic factors on yields of United States Treasury securities and on the allowed ROE provided by regulators;

• regulatory lag;

• the availability of fuel, materials and supplies, and equipment, and the potential disruptions in supply chains and inflationary pressures or tariffs on the prices and availability of commodities, labor, services, materials and supplies, elevated interest rates, and impacts associated with extended recovery periods from customers;

• the availability of a skilled work force, including transferring the specialized knowledge of those who are nearing retirement to employees succeeding them;

• maintaining affordability of electric and natural gas utility services for customers, including the demand for access to renewable energy generation at rates acceptable to customers;

• the modernization of the electric grid to accommodate a two-way flow of electricity and increased capacity for distributed generation interconnection;

• net metering rules and other changes in existing regulatory frameworks and recovery mechanisms to address the allocation of costs to customers who own generation resources that enable them both to sell power to us and to purchase power from us through the use of our transmission and distribution assets;

• legislation or programs to encourage or mandate energy efficiency, energy conservation, and renewable sources of power, and the lack of consensus as to how those programs should be paid for;

• pressure and uncertainty on customer growth and sales volumes in light of economic conditions;

• distributed generation, energy storage, technological advances, and energy-efficiency or conservation initiatives;

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• changes in the structure of the industry as a result of changes in federal and state laws, including the formation and growth of independent transmission entities;

• changes in the allowed ROE, including ROE incentive adders, on FERC-regulated electric transmission assets;

• the availability of fuel and fluctuations in fuel prices;

• the availability of materials and equipment, and the potential disruptions in supply chains;

• the availability of a skilled work force, including transferring the specialized knowledge of those who are nearing retirement to employees succeeding them;

• inflationary pressures on the prices of commodities, labor, services, materials, and supplies, high interest rates, and impacts associated with extended recovery periods from customers;

• maintaining affordability of electric and natural gas utility services for customers;

• the potential for reduced efficiency and productivity due to challenges of hybrid remote working arrangements for non-field employees;

• regulatory lag;

• the influence of macroeconomic factors on yields of United States Treasury securities and on the allowed ROE provided by regulators;

• higher levels of infrastructure and technology investments and adjustments to customer rates associated with the refund of excess deferred income taxes that have resulted in, and are expected to continue to result in, negative or decreased free cash flow, which is defined as cash flows from operating activities less cash flows from investing activities and dividends paid;

• the demand for access to renewable energy generation at rates acceptable to customers;

• public concerns about the siting of new facilities, and challenges that members of the public can assert against applications for governmental permits and other approvals required to site and build new facilities that can result in significant cost increases, delays and denial of the permits and approvals by the regulators;

• complex new and proposed environmental laws including statutes, regulations, and requirements, such as air and water quality standards, mercury emissions standards, limitations on the use of natural gas in generation, CCR management requirements, and potential CO 2 limitations, which may limit, or result in the cessation of, the operation of electric generating units;

• public concerns about the potential environmental impacts from the combustion of fossil fuels;

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• certain investors’ concerns about investing in, as well as certain insurers’ concerns about providing coverage to, utility companies that have coal-fired generation assets;

• increasing scrutiny by investors and other stakeholders of ESG practices;

• aging infrastructure and the need to construct new power generation, transmission, and distribution facilities, which have long time frames for completion, with limited long-term ability to predict power and commodity prices and regulatory requirements;

• public concerns about nuclear generation, decommissioning, and the disposal of nuclear waste;

• industry reputational challenges resulting from alleged or actual legal, regulatory or compliance failures, including in connection with lobbying and political activities or liabilities arising out of wildfires or other catastrophic events;

• consolidation of electric and natural gas utility companies.

• scrutiny by investors and other stakeholders of industry practices;

• public concerns about nuclear decommissioning and the disposal of nuclear waste;

• industry challenges resulting from alleged or actual legal, regulatory or compliance failures, including in connection with lobbying and political activities or liabilities arising out of wildfires or other catastrophic events;

• effects of mergers, acquisitions, and divestitures within the utility industry.

We are monitoring all these issues.

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For additional information, see Risk Factors under Part I, Item 1A, Outlook in Management’s Discussion and Analysis of Financial Condition and Results of Operations under Part II, Item 7, and Note 2 – Rate and Regulatory Matters, Note 9 – Callaway Energy Center, and Note 14 – Commitments and Contingencies under Part II, Item 8, of this report.

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OPERATING STATISTICS

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(b) Includes $119 million, $113 million, and $104 million in 2024, 2023, and 2022, respectively, of electric operating revenues from transmission services provided to Ameren Illinois Electric Distribution.

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Electric Operating Statistics – Year Ended December 31,

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Sioux Energy Center 0.6 0.6 0.7

Rush Island Energy Center (scheduled to be retired in October 2024) 0.4 0.4 0.4

Meramec Energy Center (retired in December 2022)

Rush Island Energy Center (retired in October 2024) — 0.4 0.4

Coal generation total 1.6 1.9 2.0

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Rate base total $ 27.7 $ 25.8 $ 23.6

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AVAILABLE INFORMATION

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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 1. Business