Ahoy, Kirsten!
GTY staterooms, or "guaranteed" staterooms are rooms that are guaranteed to be in the
category a Guest pays for, or better. Guaranteed rooms can be assigned between 30 days to one week before your sail date. If you haven't received your stateroom assignment by the time your cruise is a week out, I would recommend calling Disney Cruise Line at (800)951-3532 for more information regarding your reservation.
From time to time, a Guest with a GTY reservation may find that the category that they reserved is sold out. In this circumstance, your sailing party will be assigned a higher category stateroom at the guaranteed price of the lower category room. You never know - you might get lucky and get a magical upgrade!
I hope this helps with your planning. Wishing you a Disney Cruise Line vacation full of magical memories!
Anchors Aweigh! - Diane W.