I completed my Roth Conversion in December and I want to avoid a penalty and file the form that specifically tells the IRS when I made my conversion. Otherwise the IRS will assume I made it in the beginning of the year and will subject me to a penalty for not paying in the first three quarters. I have completed Form 8606 for my conversion and Form 1040 ES to determine my estimated tax. I was told to file Form 2210 for this but I do not see anywhere o the form that does indeed let the IRS know that I made my entire conversion in December. If it is Form 2210 that I need to file, where does this information go on the form? If not then what form do I need? I am recently retired and this is my firs rodeo with this. Moving forward I plan to convert monthly and pay estimated taxes each quarter. Thank you in advance for the assistance.