Southwest Airlines is making major changes to its baggage policy, marking a departure from its long-standing tradition of offering two free checked bags to all passengers. Starting May 28,

Customers with the highest loyalty status will be spared from the fee, but others will have to pay for checked bags for flights booked from May 28.

Southwest Airlines will begin charging customers a fee to check bags. It's a significant change for the budget carrier, which built years of advertising campaigns around its policy of letting passengers check up to two bags for free.