In December 2018 I decided to make a large conversion from my Traditional IRA to my Roth IRA. I also paid the estimated tax on the conversion as my 4th qtr estimated tax payment. There had been no underpayment as the income only occurred in December and I have a significant refund due because I overpaid. The 2210 indicates that there was a serious underpayment because it doesn't include the estimated tax payment I made. How can I handle this?
