Partial Plan Termination Vesting

https://www.businessofbenefits.com/2020/08/articles/403b/are-there-partial-terminations-of-403b-plans/

The information in this article, while interesting (and I didn't bother to evaluate it), makes no difference to us, as our plans provide for 100% vesting upon full or partial termination anyway. I expect most plans do...

403(b) plans?

Yes.

Good article and useful information.  Full termination is covered in our documents but not partial.  At least not in the 403(b) documents we use.  It references the applicable law so you are back where you started.  Almost all of our 403(b) plans use 100% vesting for all employer contributions, though.