After i get my palate expander removed, will i need a retainer?

Yes: Depending on the degree of expansion, you may have a transpalatal arch to maintain the width for a period of time. At the end of orthodontic therapy, you will always need a retainer and many follow up appointments to check for relapse and make the necessary intervention. Consult with your orthodontist.

Yes: There is always what is called relapse when palates are expanded. Relapse is the tendency for things to go back like they were. Usually the palate is expanded a bit extra to account for this relapse. All orthodontic cases require retainers, but adults have to be especially careful. Wear your retainer consistently, in some cases for life, to make sure you don't get any unwanted change.

Qualified yes: If palatal expansion completed and no additional rx now or in the future, you will need a retainer. It's not like pouring concrete. You have a whole new skeleton every 7 years. So if you want stability, wear retainer exactly as directed.