If your prepaid balance is more than 12 months, please wait until your existing membership has a prepaid balance that is less than 12 months before redeeming the 24-month Ultimate membership through Xbox All Access. If you’re already a Game Pass Ultimate member with a prepaid balance of less than 12 months, your current Ultimate time will stack with the 24 months of Ultimate that is included with Xbox All Access. Yes! And there's no need to wait for your current membership to expire.