Customers are growing more satisfied with airline loyalty programs, but confusion still reigns among many with how these frequent fliers rewards actually work, a new report says.

"Half of general loyalty program members say they do not completely understand how their program works and, among status members, 30 percent say they do not completely understand their program," J.D. Power writes in its 2018 review of airline loyalty program customer satisfaction ratings.

The consulting firm found that airlines are working harder to explain how their programs work, but that there is still a lot of room for improvement.

Airline loyalty program member satisfaction climbs 123 points (on a 1,000-point scale) when members understand how to redeem points and 131 points when they understand how to earn points, the consulting firm noted.

"Airlines have worked hard over the past several years to demonstrate the value of their loyalty programs, particularly to general members," said Michael Taylor, travel practice lead at J.D. Power.

The report noted that 75 percent of airline loyalty program members surveyed said that they save their points to cash in on larger rewards. About 13 percent of flyers reported that they preferred to redeem their point sooner for a quick discount.

J.D. Power conducted the airline loyalty satisfaction survey based on four factors. In order of importance to flyers were earnings and redeeming rewards; program benefits; account management; and member communication.

Data was collected from 3,025 respondents aged 18-95 who were in U.S.-based rewards program during May and June.

The following airlines, in ascending order, had programs with the best customer satisfaction ratings:

6. United Airlines MileagePlus

United Airlines has added a MileagePlusX app that gives members the ability to use flight points for purchases at restaurants and other participating stores. The frequent flyer program ranked last with a score of 747.