While that is the normal rule, the three-year period for filing returns and claiming refunds was extended for 2019 federal tax returns because of the pandemic. Profit and prosper with the best of ...
You are not under an affirmative obligation to file an amended tax return. But you still may want to. If you do, you can’t cherry-pick. You can't make only those corrections that get you money ...
After that the 2019 tax year is considered closed with respect to “claims for refund.” Taxpayers should do everything possible to file electronically and avoid filing returns on paper.