The partial government shutdown, now in its 25th day, will cost Delta Air Lines $25 million in lost revenue this month.
CEO Ed Bastian said on CNBC that fewer government contractors are traveling.
He also said the shutdown could delay the launch of the new Airbus 220 jet, which is scheduled to go into service on January 31 from New York's LaGuardia. FAA inspectors, who are currently furloughed, need to certify the airline's operational plans.
Airports are also feeling the pinch. At Delta hub Atlanta Hartsfield-Jackson, travelers experienced long lines Monday at TSA checkpoints because so many officers were absent.