Our goodwill and identifiable intangible assets relate to the airline segment. We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. We assess the value of our goodwill and indefinite-lived assets under either a qualitative or quantitative approach. Under a qualitative approach, we consider various market factors, including certain of the key assumptions listed below. We analyze these factors to determine if events and circumstances have affected the fair value of goodwill and indefinite-lived intangible assets. If we determine that it is more likely than not that the asset may be impaired, we use the quantitative approach to assess the asset's fair value and the amount of the impairment. Under a quantitative approach, we calculate the fair value of the asset incorporating the key assumptions listed below into our calculation.

We value goodwill and indefinite-lived intangible assets primarily using market and income approach valuation techniques. These measurements include the following key assumptions (1) forecasted revenues, expenses and cash flows, (2) current discount rates, (3) observable market transactions and (4) anticipated changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals). These assumptions are consistent with those that hypothetical market participants would use. Because we are required to make estimates and assumptions when evaluating goodwill and indefinite-lived intangible assets for impairment, actual transaction amounts may differ materially from these estimates. We recognize an impairment charge if the asset's carrying value exceeds its estimated fair value.

Changes in certain events and circumstances could result in impairment or a change from indefinite-lived to definite-lived. Factors which could cause impairment include, but are not limited to (1) negative trends in our market capitalization, (2) reduced profitability resulting from lower passenger mile yields or higher input costs, (3) lower passenger demand as a result of weakened U.S. and global economies or other factors, (4) prolonged interruption to our operations, (5) changes to the regulatory environment, (6) operational or performance changes by other airlines and (7) strategic changes to our operations leading to diminished utilization of the intangible assets.

Identifiable Intangible Assets. Indefinite-lived assets are not amortized and consist of routes, slots, the Delta tradename and assets related to alliances and collaborative arrangements. Definite-lived intangible assets consist primarily of marketing and maintenance service agreements and are amortized on a straight-line basis or under the undiscounted cash flows method over the estimated economic life of the respective agreements. Costs incurred to renew or extend the term of an intangible asset are expensed as incurred.

During the December 2025 quarter, we performed qualitative assessments of goodwill and indefinite-lived intangible assets, including applicable factors noted above, and determined that there was no indication that the assets were impaired. Our qualitative assessments include analyses and weighting of all relevant factors that impact the fair value of our goodwill and indefinite-lived intangible assets. We previously performed quantitative assessments in the December 2023 quarter, noting no impairment of goodwill or indefinite-lived intangible assets.


Goodwill and indefinite-lived intangible assets by category
	Carrying Value at
(in millions)	December 31, 2025		December 31, 2024
Goodwill	$	9,753	$	9,753
International routes and slots	2,583		2,583
Airline alliances	1,863		1,863
Delta tradename	850		850
Domestic slots	622		622
Total	$	15,671	$	15,671


Definite-lived intangible assets by category
	December 31, 2025				December 31, 2024
(in millions)	Gross Carrying Value		Accumulated Amortization		Gross Carrying Value		Accumulated Amortization
Marketing agreements	$	730	$	(717)	$	730	$	(712)
Maintenance contracts	192		(158)		192		(154)
Other	54		(53)		54		(53)
Total	$	976	$	(928)	$	976	$	(919)

Amortization expense was $8 million for the year ended December 31, 2025 and was $9 million for the years ended 2024 and 2023. Based on our definite-lived intangible assets at December 31, 2025, we estimate that we will incur approximately $7 million of amortization expense annually from 2026 through 2030.