Probably is seeing that you have to fill out Page 4 of Form 2210AI to indicate that you have an "Annualized Income." Turbo tax kept showing I had a penalty. It was because I had a $50,000 IRA conversion in October and thus it thought I had underpaid taxes in the earlier part of the year. The 2210AI page 4 allows you to account for this. It was not an error in Turbo tax as some would have you believe.
