Allegiant supports our U.S. active and reserve duty military and military veterans by offering select free benefits. The Allegiant Honors program provides several benefits to current U.S. service ...

Allegiant, however, becomes just the second U.S.-based airline to charge a carry-on luggage fee. Spirit Airlines started charging customers up to $45 per carry-on bag in 2010.

The weight limit for checked bags on Spirit and Allegiant is 40 pounds, not the standard 50 pounds allowed at major airlines and Frontier. Overweight bag charges apply in all cases. 5.

For most of the airline's domestic US flights, it costs $30 to check one bag and $40 to check a second. Any additional bags will cost $150 each to check. Prices may vary depending on location.