I also took a large distribution from my 401k this year and rolled it immediately over to an IRA, and this year, TurboTax keeps "insisting" that I need to make large Estimated Tax payments for 2021. I came to this forum to research this very question. Sure enough, it seems to be the 401k distribution that triggered TurboTax's "insistence." It's a little annoying. The program KNOWS I rolled the distribution over and that it's a non-taxable event. So .... Oh, well. I just thought I'd chime in, too, in case others encounter the same thing.
