Frequent Flyer Programs reward airline customers for their loyalty by awarding them “miles,” or program points. Miles can be redeemed for free flights, first class upgrades, and other privileges and perks.

As the name implies, the primary way that you earn miles is by flying. Typically, you earn one mile for each actual mile you travel in flight. Programs that award miles using this method usually have a minimum number of miles you can earn for a segment. For example, if the minimum number of miles per segment is 500 miles, and your flight was actually only 350 miles long, you would still be awarded 500 miles. There are also programs that award a fixed number of points per itinerary or segment, though these are less common. You will almost always earn more miles by flying first class or business class.

The major frequent flyer programs in the U.S. are:

  • American Airlines AAdvantage
  • Delta SkyMiles
  • United Mileage Plus
  • US Airways Dividend Miles

How and Where to Join

Most frequent flyer programs are free to join, and you can usually fill out an application right when you check in for a flight. Which program you should join depends on a number of factors, such as who the primary carrier is at the airports you use most frequently. For example, the closest airport to me is Detroit, which is a Delta hub, so it made the most sense for me to join the Delta SkyMiles program.

Note that, in most cases, you cannot transfer mileage you earn in one carrier’s program to any other carrier’s program. For that reason, you should try to pick one program, and consistently fly with that airline and its partners.

Maximize Your Mileage

Read the rules of your frequent flyer program carefully to ensure that you earn the maximum number of miles possible per trip. In many cases, you can earn more miles by intentionally booking an itinerary with more segments, or an itinerary with connections that are further away. Often, such changes cause very little difference in the cost of your itinerary.

If you travel for work, you might be wondering what happens if your employer pays for the trip. The answer is, in most cases, you get the miles, not your employer. The miles typically go to the person physically sitting in the seat, not the person who paid for the ticket. Consequently, this also means that if you bought a ticket for a family member, you do not get to claim their miles.

Expiration of Miles

The following table describes if and when miles expire for each of the major frequent flyer programs.

Updated on 5/7/2012

Program Miles Expiration
American Airlines AAdvantage Miles do not expire as long as there is qualifying account activity at least once every 18 months.
Delta SkyMiles Miles do not expire.
United Mileage Plus Miles do not expire as long as there is qualifying account activity at least once every 18 months.
US Airways Dividend Miles Miles do not expire as long as there is qualifying account activity at least once every 18 months.