Delta is making it harder to get into its airport lounges after they were flooded by travelers

Delta Air Lines is making the most exclusive corners of the airport harder to get into.

Next year, the airline will increase the prices and requirements to gain access to its Sky Club airport lounges, spaces designed to offer flyers an escape from the traveling masses with complimentary food and drinks, workspaces, comfortable seats, and couches. Sometimes, even showers are available.

Delta’s move comes after complaints from travelers about long lines and crowds at some of the Sky Clubs, as entrants to the spaces have increased through credit card deals, customers’ travel habits and lounge memberships.

Starting early next year, membership packages for Delta’s lounges will only be available to members of the airline’s SkyMiles frequent flyer program who have status, one of the so-called Medallion tiers. Currently, anyone can purchase a membership.

“We want to invest in our customers who invest in us,” Dwight James, Delta’s senior vice president of customer engagement and loyalty, told CNBC.

James said feedback from passengers has shown they want to avoid stressful crowds and lines at the airline’s lounges.

“It’s not representative of the experience they’re accustomed to,” he said of the recent crowding. James added that some of the most crowded lounges have been at hub markets such as New York and Atlanta, and that Florida has also been busy.

“We have to evolve,” James said.

Among other changes: Delta is raising membership fees. Starting Jan. 1, the price of an individual membership to Delta’s Sky Clubs will increase from $545 or 54,500 miles to $695 or 69,500 miles. Executive membership, which includes guests, will rise from $845 or 84,500 miles to $1,495 or 149,500 miles.

Delta offers its Diamond Medallion members certain perks for the year, such as upgrade certificates. For those who reach that level for 2024, Executive Membership to the lounge will count as three selections, up from two. And starting in February, Delta won’t offer individual memberships through that channel.

The airline recently rolled out special VIP lines for certain Sky Clubs so its most loyal customers aren’t forced to wait for entry. In July, it said customers can get into Sky Clubs within three hours of their departure time, a measure aimed to avoid crowding.

In December, Delta said it will report how busy clubs are in Detroit and Atlanta, from “not busy” to “extremely busy” so travelers know what to expect.

Delta and other carriers have made it harder to earn status and other perks over the years, awarding those tiers to not only frequent flyers but big spenders. Still, travel rewards and co-branded credit cards, like Delta’s partnership with American Express or American Airlines‘ with Citi have allowed travelers to rack up miles and perks.

Airlines have opened larger lounges or new formats to accommodate flyers.

“We look at least seven to 10 years in the future,” Calum Laming, British Airways’ chief customer officer, told CNBC at the unveiling of the large joint lounges with partner American Airlines at John F. Kennedy International Airport on Tuesday.

And United Airlines, for example, earlier this month opened a grab-and-go lounge for travelers at its Denver hub, a new type of space for travelers with limited time and one that frees up other United Club’s for other travelers who want to linger.