Frontier Group Holdings, Inc.

Item 2.05 Costs Associated with Exit or Disposal Activities. On August 25, 2026, Frontier Airlines, Inc. (“Frontier”), a wholly owned subsidiary of Frontier Group Holdings, Inc. (the “Company”), entered into an agreement with lessors of 13 A320neo aircraft currently in operation to terminate the leases associated with such aircraft that were otherwise scheduled to expire in the next six to seven years (the “Early Return Agreement”). These 13 aircraft are scheduled to be returned during the second half of 2026, resulting in an expected reduction of approximately $260 million in both the Company’s operating lease right-of-use assets and operating lease liabilities, and the elimination of meaningful maintenance-related costs that would have otherwise been expected to be incurred during the remaining lease term significantly in excess of the early lease termination costs. The Early Return Agreement is expected to result in non-cash charges largely comprised of (i) a write-off of non-recoverable capitalized prepaid maintenance balances recorded in other assets and associated with certain engines for which no future maintenance will be performed and (ii) accelerated depreciation related to capitalized maintenance recorded in property, plant and equipment due to shortened useful lives. The Company expects to recognize these non-cash charges in the third and fourth quarters of 2026 and anticipates the charges to range between $60 million and $80 million in total. Additionally, the Early Return Agreement is expected to result in cash charges in the range of $90 million to $120 million in connection with early lease termination and return of aircraft and engines to Carlyle to be recognized largely in the third and fourth quarters of 2026, with the majority to be settled in 2028 and 2029.

Item 8.01 Other Events On August 29, 2026, Frontier entered into an agreement with AerCap Holdings N.V. to direct lease 10 A321neo aircraft, with deliveries expected between the fourth quarter of 2026 and the first quarter of 2027. This transaction, along with the Early Return Agreement, maintains similar capacity with less aircraft, highlighting the productivity and flexibility of the A321neo aircraft. Cautionary Statement Regarding Forward-Looking Statements and Information Certain statements in this Current Report on Form 8-K should be considered forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based on the Company’s current expectations and beliefs with respect to certain current and future events and anticipated financial and operating performance. Words such as “expects,” “will,” “strive,” “guidance” and similar expressions are intended to identify forward-looking statements. Additionally, forward-looking statements include statements that do not relate solely to historical facts, such as statements that identify uncertainties or trends, discuss the possible future effects of current known trends or uncertainties, or indicate that the future effects of known trends or uncertainties cannot be predicted, guaranteed or assured. These risks and uncertainties include, but are not limited to, those set forth in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 (including in Part I, Item 1A. Risk Factors and Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations), and other risks and uncertainties disclosed from time to time in the Company’s other filings with the Securities and Exchange Commission. All forward-looking statements in this Current Report on Form 8-K are based upon information available to the Company on the date of this report. The Company undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events, changed circumstances or otherwise, except as required by applicable law.