in the absolute sense No you are not required to file if you are due a refund. This also assumes the amendment would have no effect on other years. The issue is that the IRS may have received tax forms reporting those missing investment sales but will not know about those deductions. In that case the IRS is likely to send you a bill and then you'll have to submit an amended return. At that point Turbotax for that year may not be supported, so you would have to do the amended return manually. so maybe as a minimum you prepare the amended returns but wait to see if you get a notice. Also, do you have a state return that would also be affected by the missing info?
