TurboTax is calculating an IRS penalty for a Roth conversion and Estimated Tax Payment in 4Q2025.

[jamesfsmithco]

I made a sizable Roth conversion in Dec 2025 and immediately paid the estimated taxes for it.  However, it appears that TurboTax is calculating that a penalty is due.  There is a reply to this situation from about 6 years ago but it requires annualizing all of my income.  Surely there must be a simpler solution to this common situation.

[dmertz · Accepted solution]

"Surely there must be a simpler solution to this common situation."

Nope.  The arduous task of annualizing income is necessary.  Avoiding the need to annualize would have required increasing tax withholding or making estimated tax payments for the earlier tax quarters.

[baldietax]

not unless you met the safe harbor on Form 2210 based on prior year tax, otherwise you'll need to annualize