I searched through this forum on a number of keywords, and read through the Marriott Rewards Ts and Cs, and can't find a consistent answer.

Do Marriott points expire? Do accounts get cancelled after a certain period of inactivity?

With the expiration dates applied to Hhonors and SPG points and the expiration that is in the Hyatt Ts and Cs (but apparently not enforced), and the increasing tendency of airline programs implementing 36 or 18 month expiration periods, I wonder what Marriott's policy is/will be.