My SO and I are almost 50, both SSDI; If we get married, my Medicaid spenddown goes up to 600. Any other way?

I say, what's the point in making it "legal"? That's just in the eyes of the courts, not in your hearts. I wouldn't even bother changing names, unless that's what you really want. You can even have a ceremony of your commitment to each other, but without a license. You don't need a piece of paper to prove you are married in your hearts. I've been married 3 times, and at 51, don't consider myself a 'senior'. But I would not get married again legally. I would consider doing a ceremony of commitment as I suggested above.