Hi Stacey!
Thanks for your question and for visiting the Disney Parks Moms Panel!
Your question covers one of my all-time favorite things to do at
Walt Disney World...
Mickey's Very Merry Christmas Party at
Magic Kingdom!! This is a MUST DO for me and my girls EVERY time we visit during the holiday season. I would absolutely recommend that you try to attend.
The Party (MVMCP) is a separate, "hard ticket" event, which means that it requires a separate, additional admission to attend beyond regular theme parks hours. The Party runs from 7 PM-midnight, but guests attending the party who may not have been in Magic Kingdom on that day may enter as early as 4 PM!!
This means that with your Party ticket, you can enter once you arrive at Magic Kingdom and it will NOT cost you one of your regular admission days from your trip. Pretty cool timing!!
I hope this helps and I wish you a Magical trip!!
Chris