Edit:
I don't think WGT has devolved divulged that. I can tell you that I made Master at around 65.7, but that was long ago. With a quick check of your stats, you could be there soon. For example, a 31 on your next rated 9 hole round is probably all it would take. I'm not encouraging Sandbagging, but play smart...after making Master there is no going back...and you'll be playing with the best gamers around. If a player is not ready for that, they'll wish they were back in the Pro's. If this is a concern, just post all your scores and play your best...then you'll play in the Tier that is right for you. The problem comes when players post only their best scores and move up too quickly.
Joey