For tax year 2017 Federal income tax returns, the normal April 15 deadline to claim a refund has also been extended to May 17, 2021. The law provides a three-year window of opportunity to claim a refund. If taxpayers do not file a return within three years, the money becomes property of the U.S. Treasury. The law requires taxpayers to properly address, mail and ensure the tax return is postmarked by the May 17, 2021, date.

Additionally, foreign trusts and estates with federal income tax filing or payment obligations, who file Form 1040-NR, now have until May 17, 2021.