According to the IRS, overpayments totaling $950 million may be waiting for an estimated one million taxpayers who did not file a federal income tax return for 2012. To collect the money, these taxpayers must file a 2012 tax return with the IRS no later than this year’s April tax deadline.

That is because the statute of limitations on refunds is generally 3 years from the due date of the return.  The 2012 tax returns were due April 15, 2013; three years from that is this year’s due date of April 18, 2016.  A holiday in D.C. extends the deadline this year.