They don't transfer into any other programs, but there are other redemption offers, besides those listed on the Frontier website. I am not sure if the minimal 4,000 mile balance qualifies for anything other than magazines, https://www2.magsformiles.com/10012393/splash.html, but I suggest calling the ER department at 866-263-2759 to check on other options, before the miles expire.

The 4,000 mile balance can be kept current by partner activity, such as car rental, hotel stay http://www.frontierairlines.com/freq...artners/hotels,floral order http://www.frontierairlines.com/freq...artners/floral, or shopping at the ER Mall https://www.skymall.com/frontiermall...dwestmilesmall and having the miles posted to your account. If you are running really short on time, until a mile-posting transaction will post, ask the EarlyReturns department to courtesy-credit your account (one mile), which will extend the account so that the existing miles don't expire, before any newly-earned miles are credited to your account. If you do that, it's best to make the appropriate purchase in advance, and then contact them; they will most likely ask for a copy of the transaction for proof.