The company said it's the only major U.S. air carrier to offer miles benefits that don't expire. Under the plan, each mile a passenger travels count as points that add up for a variety of benefits, like free travel. Now the points won't expire if they go unused after 24 months, as was previously the case.
The change will affect all accounts active at the beginning of this year. The SkyMiles program is 30 years old, making it one of the longest-running loyalty programs in the travel industry.
Shares of Delta rose 10 cents to $11.92 in afternoon trading.