Originally Posted by DragonMartini

There may be some other way to do it, but in my case I simply e-mailed Marriott indicating that I had elite status with another chain (SPG) and was curious if they would status match. They indicated they don't, but offered a stay X nights in Y months challenge.

I think it was 12 nights in 3 months for Gold. I've heard about 18 nights for Platinum. I won't swear to either number and don't have the means of looking it up right now.