Exhibit 15

October 9, 2026

To the Board of Directors and Stockholders of

Delta Air Lines, Inc.

We are aware of the incorporation by reference in the Registration Statements (Form S-3ASR No. 333-284844, 333-297387 and Form S-8 No.’s 333-142424, 333-149308, 333-154818, 333-151060, 333-212525 and 333-288620) of Delta Air Lines, Inc. for the registration of its securities of our report dated October 9, 2026 relating to the unaudited condensed consolidated interim financial statements of Delta Air Lines, Inc. that are included in its Form 10-Q for the quarter ended September 30, 2026.

/s/ Ernst & Young LLP