Declining a school after accepting the offer

Notify the programs ASAP. Give them the ability to accept someone else. Expect that your desposit is non-refundable unless you were informed otherwise.

I imagine it is not thrilling for a program to hear someone they were counting on is backing out, but that’s why they have waitlists. Thank them for the opportunity, let them know you are withdrawing from your seat for another program. The sooner you do this, the better for other people who were waitlisted. ?

Schools are used to this - it's not rare. As others have mentioned, thank them for the opportunity. If you feel the need to go into further detail, you can just put something such as another matter came up that won't allow you to attend. Plain and simple.

Of course, no deposit(s) will be returned.

Yes tell them now. It will change someone's life getting called off the waitlist.

In a similar fashion,

I have a hospital job offer but I'm wondering if I should accept it while I wait for other opportunities before November.

Any idea on how this plays out contractually or if the former hospital will never consider me again, etc? Any strategies?

Yes, I was in the position and actually withdrew from a program in the middle of my first week after finding out I was accepted to my first choice program that was scheduled to start months later (was shocked, honestly.) It was hard to word, but I was honest with them and they were able to fill my position with another student quickly. Program directors and faculty don't take it personally, but as the field is a rather small community, be professional and direct.

I just withdrew my seat after being accepted elsewhere, hopefully someone will hear back from the waitlist!