Under a Transportation Department rule that was upheld by a federal appeals court, airlines must display the total cost of a ticket in the largest type size and have it be the most prominent price in ads or on their web pages. Airlines still can break down the price of a ticket to show taxes and fees.
The justices on Monday rejected an appeal filed by Spirit Airlines, Allegiant Air and Southwest Airlines of the ruling by the U.S. Circuit Court of Appeals for the District of Columbia.
The case is Spirit Airlines v. U.S. Department of Transportation, 12-656.