your FREE SPIRIT miles can expire. If you have less than 2,000 miles posted to your account from any source during the previous 6 month period, miles older than 6 months will be expired. Because the FREE SPIRIT program calculates your status on a monthly basis, any miles that will expire will do so at the start of every month. If you want to keep your miles, get a FREE SPIRIT MasterCard and make just one purchase per month - then your miles will never expire.

Credits expire one year from their date of posting in your account.