Was curious if you could challenge status with Marriott and so I called MR up. You can, there is no fee to enroll and you get up to 4 months to complete as long as you enroll on or after the 1st of the month. They cannot pre or post date your enrollment so you must call in on the day that you want to enroll. Also, you are upgraded to the status you are challenging immediately. It's very important to make sure you can complete the challenge. If not, you are banned from challenging for a year. Here's the challenge info. Silver: 3 separate stays Gold: 6 separate stays Platinum: 9 separate stays From my understanding, you cannot qualify based on nights anymore. I will keep my challenge status up-to-date in my signature for those who may be interested. Wish me luck!!