Thanks! I'll know for sure next year -- right now I can't do a dry run, because I have to use the 2017 TurboTax to estimate my 2018 taxes, and since in 2016 I had no taxable income (living only on SS), I am "exempted" from the penalty for that reason. But I have filled out 2210 with the 2018 withholding for each quarter, and checked the box indicating the reason for the larger 4th quarter payment (didn't receive the income until that quarter). So your suggestion put me on the right track. Thanks again!
