is adding Park Hopper retroactive?

[scrappinginontario]

I’m so glad Came across this thread because I was under the assumption it was for the remainder of the ticket, I wasn’t aware it would be retroactive!
I’m debating if it’s worth it to upgrade. If the park we want to hop to is at capacity will we be able to get in? MK is showing unavailable on Halloween party days. So does that mean we can’t hop to the park? I’m so confused. I’m having a hard time planning this one trip!

I just got 2 different answers. Can anyone confirm if you can hop to a park that shows no availability to reserve for that particular day?

The thread you want to look at is the 'Everything Park Hopping' thread. Reading post 1 will be very beneficial to you.