Hi Jan!
What a fantastic trip you have coming up just around the corner. Spending 12 -13 days at the Walt Disney World Resort sounds like a perfect vacation to me!
As you indicate, 10 days is the maximum length of time currently available for United States residents when purchasing a multi-day
Theme Park Ticket. Therefore, if you wish to spend 11 days visiting the four Walt Disney World Theme Parks, you would have to purchase an additional 1 Day ticket.
However, you do have other options. You may wish to consider adding the
Water Parks Fun & More Option to your 10 Day Park Hopper Ticket. This option provides you 10 daily passes to be used within 14 consecutive days of activating your 10 Day Park Hopper Tickets at your choice of Blizzard Beach Water Park, Typhoon Lagoon Water Park, ESPN Wide World of Sports Complex, or various golfing options. You can choose a different experience each day and you can visit on days when you will also be visiting a Walt Disney World Theme Park or not; it is up to you. The best part...adding this option to your 10 day Park Hopper Ticket is currently only $26, making it (in my opinion) the best deal on property!
Another option if you want to spend an 11th day at one of the four Walt Disney World Theme Parks would be to purchase an
Annual Pass, especially if there is a chance you may return to visit again within a year. As an Annual Passholder, you could also take advantage of many special
Passholder discounts and benefits during your trip.
Whichever option you choose, I wish you a most wonderful vacation at the place where the Magic is Endless!
Trish