Hi Tracy!
Thanks so much for visiting the Disney Parks Moms Panel!
Upgrades to your Park Tickets may be processed at Walt Disney World any time within 14 days of the first use of the tickets, providing that the ticket(s) have remaining admissions. You may choose to add extra park days, the Water Parks Fun & More Option, Park Hopper Option, No Expiration Option or even upgrade to an Annual Pass.
The pricing to process these upgrades at the park is the same as online pricing. However, if you were to choose to add the Park Hopper to your tickets upon arrival or before leaving home, the option would be added to the entire length of your ticket.
If you're unsure whether you'll be 'hopping' from park to park throughout your visit whether it be for dining reservations or just because you like to mix things up in a day, you may wish to consider starting out with a Base Ticket and deciding on whether you need the extra options after your arrival.
I've included a link to the
Frequently Asked Questions page regarding Tickets on the My Disney Experience website. I hope this information is helpful to you Tracy!
If you have additional questions, please feel free to write me back any time! I'd love to hear from you again and it would be my pleasure to assist you in the planning of your family's Magical trip to Walt Disney World!
Kirsten