The Internal Revenue Service (IRS) is sitting on nearly $1 billion owed to Americans who failed to file tax returns in 2009.

The IRS says 984,400 people did not file a federal tax return four years ago, leaving the agency with $917.4 million in unpaid refunds. Many of the cases involve people who made too little money to be required to file a tax return, but who had federal taxes withheld from their paychecks and are owed a refund. Lower-income individuals and families with children also may be owed funds as a result of the Earned Income Tax Credit.

But it’s not too late to claim money owed. An individual must file their 2009 return by April 15 of this year. There is no penalty for filing a late return that qualifies for a refund.

However, taxpayers filing for 2009 may have their refunds withheld if they haven’t filed tax returns for 2010 and 2011, or if they owe other monies to the IRS or a state tax agency, or to their spouse for unpaid child support, or to a student loan lender.

-Noel Brinkerhoff, David Wallechinsky

To Learn More:

Tax-Refund Deadline Nears (by Laura Saunders, Wall Street Journal)

IRS Unclaimed Refunds: The IRS Owes You $1 Billion (Some of You, Anyway) (by Stephen Ohlemacher, Associated Press)

$58 Billion Unclaimed: Is Some Of It Yours? (by Melanie Hicken, CNN Money)

IRS Holding $1.3 Billion in Unclaimed Refunds (by Noel Brinkerhoff, AllGov)