My elderly (95) dad received a letter from the IRS indicating that he miscalculated his 2021 AGI because he omitted his IRA RMDs. The IRS is correct, and he owes more taxes. I went over his previous years' returns with him, and he made the same mistake for multiple years (for some reason, he thought that his RMDs were not taxable -- I think he mistakenly thought that he had Roth accounts, which he does not). Should we wait until he gets letters for the prior years from the IRS or proactively file 1040X returns for the prior years? TYIA.
