The due date for making a traditional IRA contribution is generally the same as the due date of the tax return for the year of the deduction. The contribution can be made after a return is filed, but only if the contribution is made by the return due date.

A return can be amended to deduct an IRA contribution. The amended return does not have to be filed before the original return unextended due date, but the IRA contribution must have been made on or before that due date. IRA contributions mailed to a bank and postmarked no later than the tax return’s original due date are considered timely contributions. (LR 8536085)

Because of the COVID-19 pandemic the due date of individuals’ 2019 income tax returns was automatically extended by the IRS to July 15, 2020, which meant the last day for contributing to an IRA for 2019 was also extended to July 15, 2020. The 2020 1040 return due date was extended to May 17, 2021, which also became the last day for making a 2020 IRA contribution. (Notice 2021-21)