Road Warrior

Airlines are changing their perks, testing fliers' loyalties

Harriet Baskas, Special to CNBC
Getty Images

Early boarding privileges, waived checked bag fees, free flights and upgrades from the back of the plane to the front are just some of the benefits air travelers have come to expect from airline loyalty programs.

Yet program changes rolled out last year by some major U.S. carriers (notably Delta and United) made attaining the status needed to earn those perks much harder to achieve.

Experts say that in 2016, the estimated 65 million U.S. travelers who are loyalty program participants should expect more of the same.

"The programs are becoming more complicated," said Gary Leff, a travel expert who writes about points and miles on the View From the Wing blog. Leff said fliers are being rewarded more on how much they spend, not on how many miles they've flown, "and they're getting less rewarding." Many cabin award tickets, especially the premium variety, now cost more on Delta, United and — starting in March — on American Airlines, as well.

Read MoreVacation planning? Check out these 2016 hot spots

Still, the news isn't all bad. Some airlines, such as Alaska and Hawaiian, continue to award points based on miles flown. Others are adding new benefits for elite members, and adding more ways for members to spend banked miles they can't use in the air.

As airlines move to make changes to their frequent flyer programs, data from research firm Phocuswright suggests the impact on travelers is likely to be muted. While nearly a third of U.S. flyers are "mid-tier" loyalty members, only 4 percent say they have achieved elite status, said Doug Quinby, vice president of research for Phocuswright. He said that nearly half haven't even accrued enough miles to earn any benefits.

Still, benefits or not, "loyalty does breed repeat business," said Quinby.

Sixty-two percent of loyalty program members belong to more than one program, Phocuswright said, while 78 percent of that subset said they book with those airlines at least half the time.