Hello,
Thanks for writing in!
Our licenses are perpetual - and once you own one, it won't ever "expire." If you choose not to renew your maintenance, you can continue using the product you have as long as you like. We cover this topic in a bit more detail here:
https://www.pingman.com/kb/16Hopefully this helps out! If you should find yourself with any other questions, please don't hesitate to let us know.
Best wishes,
-Gary