What changed in this filing

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Item 1. Business

2026-02-11 compared with 2025-02-11 · 44 added, 70 removed, 164 unchanged (41% of the section changed)

In 2024, the U.S.

Environmental Protection Agency (the "EPA") finalized regulations defining certain per- and polyfluoroalkyl substances ("PFAS") as "hazardous substances" under the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), and the EPA also finalized standards regulating PFAS under the Safe Drinking Water Act.

PFAS are man-made chemicals that have been used in a wide variety of consumer and industrial products, including the firefighting foams used to extinguish fuel-based fires at airports and refineries.

Numerous states have adopted regulations governing PFAS as well.

The EPA’s final rule under CERCLA, and analogous state laws could subject airports, airlines, and refineries, among others, to potential liability for cleanup of historical PFAS contamination associated with use of PFAS-containing firefighting foam.

In addition, some states have adopted legislation prohibiting the manufacture, sale, distribution and/or use of firefighting foam containing intentionally added PFAS, which may require transition to alternative fire suppression systems.

Delta has been developing plans to transition its aircraft maintenance hangars to systems that do not contain intentionally added PFAS.

The ultimate impact and associated cost to Delta of these legislative and regulatory developments cannot be predicted at this time.

GHG Emissions .

Aviation industry GHG emissions, particularly carbon emissions, and their impact on climate change have become a focus in the international community and within the U.S.

In 2016, the International Civil Aviation Organization ("ICAO") formally adopted a global, market-based emissions offset program known as the Carbon Offsetting and Reduction Scheme for International Aviation ("CORSIA").

This program establishes a goal for the aviation industry to achieve carbon-neutral growth in international aviation beginning in 2021.

Any growth above the baseline would need to be addressed using either eligible carbon offsets or a lower carbon fuel.

ICAO set the baseline for establishing airlines’ obligations under CORSIA for 2021 to 2023 based on 2019 travel, and in 2022 set a new, more stringent CORSIA baseline of 85% of 2019, which will apply from 2024 through 2035.

The pilot phase of the CORSIA program ran from 2021 through 2023, and is being followed by a first phase of the program beginning in 2024 and a second phase beginning in 2027.

Countries can voluntarily participate in the pilot and first phase, and the United States agreed to participate in these voluntary phases.

Participation in the second phase is mandatory for certain countries, including the United States.

government has not yet enacted legislation to mandate that U.S.

operators participate in CORSIA.

Nonetheless, we have voluntarily submitted verified emissions reports on our annual international emissions.

While airlines had no offsetting obligations during the pilot phase of CORSIA as a result of the impact of the COVID-19 pandemic on international travel, we expect that international airline emissions will likely exceed the new baseline during the next phase (2024 – 2026).

Because certain CORSIA program details remain to be developed and could potentially be affected by political developments in participating countries or the results of the initial phases of the program, the impact of CORSIA cannot be predicted at this time.

However, CORSIA is expected to increase operating costs for airlines that operate internationally.

Additionally, the EU requires its member states to implement regulations to include aviation in its Emissions Trading Scheme ("ETS").

Under these regulations, any airline with flights originating or landing in the European Economic Area ("EEA") is subject to the ETS and, beginning in 2012, was required to purchase emissions allowances if the airline exceeds the number of free allowances allocated to it under the ETS.

The initial scope of the ETS, however, was narrowed so that it would apply only to flights within the EEA through 2023 to align with the pilot phase of CORSIA.

In 2023, the EU adopted new legislation extending this narrow scope of the EU ETS until 2027.

It also requires a review of CORSIA’s effectiveness in 2026, which could potentially lead to expansion of the EU ETS to include all flights departing the EU and EEA.

As a result of the United Kingdom’s ("UK") withdrawal from the EU, UK flights are no longer part of the EU ETS and are instead regulated under a separate UK ETS scheme.

UK ETS is applicable to UK domestic flights and flights from the UK to EEA countries.

In 2017, ICAO also adopted aircraft certification standards to reduce carbon dioxide ("CO 2 ") emissions from new aircraft.

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These standards will not apply to existing in-service aircraft.

In 2021, the EPA finalized GHG emission standards for new aircraft engines designed to implement the ICAO standards on the same timeframe contemplated by ICAO, and these standards have been upheld in response to legal challenges.

Like the ICAO standards, the final EPA standards do not apply to engines on in-service aircraft.

The airline industry may face additional regulation of aircraft emissions in the U.S.

and abroad and become subject to further taxes, charges or additional requirements to obtain permits or purchase allowances or emission credits for GHG emissions in various jurisdictions.

For example, in 2023, the EU adopted legislation that imposes a SAF mandate on fuel supplied at EU airports.

The mandate requires that, of the jet fuel supplied in the EU, 2% must be SAF beginning in 2025, and the percentage increases incrementally over time to 70% in 2050.

This mandate is expected to increase the cost of SAF in the EU.

In 2024, the UK also adopted legislation that imposes a SAF mandate on producers that supply fuel to UK airports, and other countries are also considering similar mandates.

Delta Air Lines, Inc.

| 2024 Form 10-K

Additional regulation could result in taxation, regulatory or permitting requirements from multiple jurisdictions for the same operations and significant costs for us and the airline industry.

and abroad and could become subject to further taxes, charges or additional requirements to obtain permits or purchase allowances or emission credits for GHG emissions in various jurisdictions.

For example, in 2023, the EU adopted legislation that established a SAF mandate on fuel supplied at EU airports.

Beginning in 2025, the mandate required 2% of the jet fuel supplied in the EU to be SAF, and the percentage increases incrementally over time to 70% in 2050.

This mandate has increased SAF prices in the EU for the airline industry.

In 2024, the UK also adopted SAF mandate legislation, and other countries are also considering mandates.

Additional regulation could result in taxation, regulatory or permitting requirements from multiple jurisdictions for the same operations and significant costs to the airline industry, including Delta.

In addition to direct costs, such regulation could result in increased fuel costs passed through from fuel suppliers affected by any such regulations.

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In addition, foreign governments may enact or allow airports to enact similar restrictions, which could adversely impact our international operations or require significant expenditures in order for our aircraft to comply with the restrictions.

For example, in 2022, to reduce noise, the Netherlands announced a multi-phase plan to reduce the maximum number of flights authorized annually at Amsterdam’s Schiphol Airport.

For example, in 2022, the Netherlands announced a multi-phase plan to reduce noise by reducing the maximum number of flights authorized annually at Amsterdam’s Schiphol Airport.

In 2023, airlines and airline associations, including Delta and KLM, challenged the initial phase of the plan.

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In November 2023, the Netherlands suspended the initial phase of the plan, and in 2024, the Netherlands Supreme Court found that the Dutch government’s flight reduction plan was unlawful.

The Dutch government has issued a revised plan, which is under review with the European Commission.

Neither the outcome of the review of the plan, nor the impact of its implementation, can be determined at this time.

The Dutch government has issued a revised plan, which is the subject of renewed litigation brought by airlines, including Delta and KLM, and by groups representing residents around Schiphol Airport.

This litigation questions the lawfulness of the renewed plan.

The outcome of this litigation cannot be determined at this time.

Refinery Matters .

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Market prices for RINs have been volatile and marked by periods of sharp increases and decreases.

However, in June 2023, the EPA finalized RFS volume requirements for 2023, 2024 and 2025, which has ameliorated the historical volatility in market prices for RINs.

Civil Reserve Air Fleet Program

7 unchanged sentences

| 2025 Form 10-K

Information About Our Executive Officers

Information About Our Executive Officers as of December 31, 2025

Bastian, Age 68:

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Vice President Scheduling of Continental Airlines (1998 - 2001).

As previously announced, Mr.

Hauenstein will retire from Delta effective February 28, 2026.

Ausband, Age 63:

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Managing Director of Bank of America (1999 - September 2012).

As previously announced, Mr.

Samant will retire from Delta effective March 1, 2026.

Sear, Age 60:

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(June 2005 - October 2008).

Delta Air Lines, Inc.

| 2025 Form 10-K

Snell, Age 49:

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Chief Executive Officer of Delta Global Services and Delta Private Jets (March 2015 - November 2015).

Delta Air Lines, Inc.

| 2024 Form 10-K

Additional Information

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Although we believe that our insurance coverage is appropriate, we may be forced to bear substantial losses from an accident in the event that the coverage was not sufficient.

In addition, any accident involving an aircraft that we operate or an aircraft that is operated by an airline that is one of our regional carriers or codeshare, alliance or joint venture partners could create a negative public perception about safety and reliability for aviation authorities and the public, which could harm our reputation, resulting in air travelers being reluctant to fly on our aircraft and therefore harm our business.

Breaches or lapses in the security of the technology systems we use and rely on could compromise the data stored within them and consequently expose us to liability, disruption to our operations and damage to our reputation, any or all of which could have a material adverse effect on our business.

In addition, any accident involving an aircraft or aircraft type that we operate or that is operated by another airline, including our regional carriers or codeshare, alliance or joint venture partners, could create a negative public perception about safety and reliability for aviation authorities and the public, which could harm our reputation, resulting in air travelers being reluctant to fly on our aircraft and therefore harm our business.

Breaches or lapses in the security of the technology systems we use and rely on could compromise the data stored within them and consequently disrupt our operations, damage our reputation and expose us to liability, any or all of which could have a material adverse effect on our business.

As a regular part of our ordinary business operations, we process a high volume of information, including personal information about individuals we have a relationship with and other sensitive business information.

The secure operation of our networks and systems, and those of our business partners and third-party service providers, on which this type of information is processed is critical to our business operations and strategy.

These networks and systems are subject to an increasing threat of continually evolving cybersecurity risks, which we must manage.

These networks and systems are subject to high levels of threat of continually evolving cybersecurity risks, which we must manage.

We expect unauthorized parties to continue attempting to gain access to our systems or information, or those of our business partners and third-party service providers, including through fraud or other means of deception, or introduction of malicious code, such as malware and ransomware.

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The methods used to obtain unauthorized access, disable or degrade service or sabotage systems are constantly evolving and may be difficult to anticipate or to detect for long periods of time.

Threat actors are also increasingly leveraging advanced technologies, including the use of AI and automated tools, to enhance the scale, speed and effectiveness of cyberattacks.

As a result of these types of risks and regular attacks on our systems, we review and update procedures and processes to prevent and protect against unauthorized access to our systems and information and inadvertent misuse of data.

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However, the constantly changing nature of the threats means that we may not be able to prevent all information security breaches or misuse of data.

In addition, as cybercriminals become more sophisticated, the cost of proactive defensive measures continues to increase.

In addition, as cybercriminals become more sophisticated, including through the use of AI-enabled technologies, the cost of proactive defensive measures continues to increase.

We are also subject to evolving global privacy and security regulatory obligations and an increasing customer focus on privacy issues and data security in the United States and abroad, as well as to geopolitical risks associated with international data transfer.

The compromise of our or our business partners’ or third-party service providers’ technology systems could result in legal claims or proceedings, liability, fines or other regulatory enforcement actions, disruption to our operations and damage to our reputation, any or all of which could adversely affect our business.

The compromise of our or our business partners’ or third-party service providers’ technology systems could result in disruption to our operations, damage to our reputation and legal claims or proceedings, liability, fines or other regulatory enforcement actions, any or all of which could adversely affect our business.

The costs to remediate these incidents could be material.

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The operation of our technology systems and the use of related data may also be vulnerable to a variety of other sources of interruption, including natural disasters, terrorist attacks, computer viruses, hackers and other security issues.

A significant individual, sustained or repeated failure of our information technology infrastructure, including third-party networks, software-as-a-service applications, cloud services, or technology that we utilize and on which we depend, could impact our operations and our customer service, result in loss of revenue, increased costs and damage our reputation.

While we have initiatives and disaster recovery plans in place to prevent or mitigate disruptions, we experienced a global outage caused by a faulty update by cybersecurity vendor CrowdStrike in July 2024 that resulted in global information technology outages of Windows-based systems.

The faulty software update significantly affected our information technology systems, disrupting our operations.

The operational disruption resulted in flight delays and approximately 7,000 cancellations of Delta flights over five days, impacting 1.4 million customers.

The CrowdStrike-caused outage and resulting operational disruption adversely impacted our results of operations as discussed in more detail in “Item 7.

Management's Discussion and Analysis.” While we continue to invest in improvements to our preventative initiatives and disaster recovery plans, the measures we have in place may not be adequate to prevent future business disruptions and any material adverse financial and reputational consequences to our business.

While we have initiatives and disaster recovery plans in place to prevent or mitigate disruptions, we have experienced a significant disruption in the past, such as the global outage caused by a faulty update by cybersecurity vendor CrowdStrike in July 2024 that resulted in global information technology outages of Windows-based systems and significantly affected our information technology systems, disrupting our operations.

While we continue to invest in improvements to our preventative initiatives and disaster recovery plans, the measures we have in place may not be adequate to prevent future business disruptions and any material adverse financial and reputational consequences to our business.

Failure of the technology we use to perform effectively could have a material adverse effect on our business.

We are dependent on technology initiatives and capabilities to provide customer service and operational effectiveness in order to compete in the current business environment.

For example, substantially all of our tickets are issued to our customers as electronic tickets, and a significant number of our customers check in for flights using our website, airport kiosks and our FlyDelta mobile application.

We have made and continue to make significant investments in customer facing technology such as delta.com, the FlyDelta mobile application, in-flight wireless internet, check-in kiosks, customer service applications, application of biometric technology, airport information displays and related initiatives, including security for these initiatives.

We have also invested in significant upgrades to technology infrastructure and other supporting systems and a transition to cloud-based technologies.

We have made and continue to make significant investments in customer facing technology such as delta.com, the Delta app, in-flight wireless internet, check-in kiosks, customer service applications, application of biometric technology, airport information displays, new AI-based tools and services, and related initiatives, including security for these initiatives.

We have also invested in significant upgrades to technology infrastructure and other supporting systems and have largely completed a transition to cloud-based technologies.

The performance, reliability and security of the technology we use are critical to our ability to serve customers.

If this technology does not perform effectively, including as a result of the implementation or integration of new or upgraded technologies or systems, our business and operations can be negatively affected, which could be material.

New and emerging technologies, including AI‑based tools and services, may not perform as intended, may be difficult to implement, integrate or scale, or may require ongoing training, monitoring and refinement.

If our technology initiatives and capabilities do not perform effectively or accurately, including as a result of the implementation or integration of new or upgraded technologies or systems, our business and operations can be negatively affected, which could be material.

In addition, if we are unable to develop or deploy new technologies, including AI‑enabled capabilities, as quickly or effectively as our competitors, or if our investments do not deliver expected benefits, our ability to compete and meet customer expectations could be adversely affected.

As discussed above, the faulty CrowdStrike software update significantly affected our information technology systems, disrupting our operations.

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Fuel costs represented 17%, 19% and 21% of our operating expense in 2025, 2024 and 2023, respectively.

Fuel prices are highly volatile and at times have adjusted substantially in relatively short periods of time.

Between 2022 and 2024, our average fuel price per gallon has ranged from a monthly high of $4.25 in June 2022 to a monthly low of $2.29 in November 2024.

We acquire a significant amount of jet fuel from Monroe and through strategic agreements associated with the refinery that Monroe has with third parties.

Fuel prices are highly volatile and at times have increased substantially in relatively short periods of time.

Between 2023 and 2025, our average fuel price per gallon has ranged from a monthly high of $3.22 in October 2023 to a monthly low of $2.20 in August 2025.

We acquire a significant amount of jet fuel from Monroe.

The cost of the jet fuel we purchase under these arrangements remains subject to volatility, including from the cost of crude oil.

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Our aircraft fuel purchase contracts alone do not provide material protection against price increases as these contracts typically establish the price based on industry standard market price indices.

Because passengers often purchase tickets well in advance of their travel, a significant rapid increase in fuel price may result in the fare charged not covering that increase.

Because passengers often purchase tickets well in advance of their travel, a significant rapid increase in fuel price could result in the fare charged not covering that increase.

At times in the past, we often were not able to increase our fares to offset fully the effect of increases in fuel costs, and we may not be able to do so in the future.

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Shortages in fuel supplies could have negative effects on our business and results of operations.

Unplanned disruptions or interruptions of production at the refinery could have a negative impact on our ability to acquire jet fuel needed for our operations.

Unplanned disruptions or interruptions of production at Monroe's refinery could have a negative impact on our ability to acquire jet fuel needed for our operations.

Disruptions or interruptions of production at the refinery could result from various sources including a major accident or mechanical failure, interruption of supply or delivery of crude oil, work stoppages relating to organized labor issues, or damage from severe weather or other natural or man-made disasters, including acts of terrorism.

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These relationships and investments involve significant challenges and risks, including that joint ventures or cooperation agreements may be subject to ongoing review and renewal requirements and may not generate the expected financial results, or that we may not realize a satisfactory return on our investments.

For example, the DOT's approval of and antitrust immunity grant for our joint cooperation agreement with Aeroméxico is subject to a pending renewal application with the DOT, which was tentatively dismissed pursuant to an Order to Show Cause issued by the DOT on January 26, 2024.

The existing immunity remains in effect pending final adjudication of the renewal application, the timing and outcome of which cannot be predicted at this time.

On September 15, 2025, the DOT issued a final order terminating the antitrust immunity for our joint cooperation agreement with Aeroméxico and directed us and Aeroméxico to wind down certain joint operations that were covered by the immunity by January 1, 2026.

We and Aeroméxico subsequently filed a petition in the United States Court of Appeals for the Eleventh Circuit for judicial review of the DOT final order.

On November 12, 2025, the Court granted a stay of the final order pending the resolution of the case, the timing and outcome of which cannot be predicted at this time.

In the meantime, we and Aeroméxico continue to operate under the joint cooperation agreement.

We are dependent on these other carriers for significant aspects of our network in the regions in which they operate.

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A significant disruption in, or other problems with respect to, the operations or performance of third parties on which we rely, including third-party carriers, could have a material adverse effect on our business and results of operations.

We rely on the operations and performance of third parties in a number of areas that are important to our business, including third-party regional carriers, international alliance partners and ground operation providers at some airports.

While we have agreements with certain of these third parties that define expected service performance, we do not have direct control over their operations.

To the extent that the operations of a third-party on which we rely is significantly disrupted or if these third parties experience significant performance issues (including failing to satisfy any applicable performance standards) or fail to meet any applicable compliance requirements, our revenue may be reduced, our expenses may be increased and our reputation may be harmed, any or all of which could result in a material adverse effect on our business and results of operations.

To the extent that the operations of a third-party on which we rely are significantly disrupted or if these third parties experience significant performance issues (including failing to satisfy any applicable performance standards) or fail to meet any applicable compliance requirements, our revenue may be reduced, our expenses may be increased and our reputation may be harmed, any or all of which could result in a material adverse effect on our business and results of operations.

Delta Air Lines, Inc.

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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