How long does VMP membership last for Kickstarters

hoangtaybaokiem thought this was worth mentioning said

I was looking at my Casemates membership info and saw that “As a current VMP member, you’re grandfathered into the program and may continue your benefits as long as you maintain membership.”

I got started with Casemates (and meh) when Casemates started early in 2018 (IIRC), and I’m wondering if my VMP membership will come up for renewal sometime. What do I have to do the “maintain membership”?