An estimated 1 million tax payers are owed more than $1 billion in unclaimed federal income tax refunds for 2013 according to the Internal Revenue Service. In Michigan alone, the IRS estimates that 33,600 people are owed nearly $34 million in unclaimed federal income tax refunds for 2013.

Of course, taxpayers have plenty of reasons for not filing tax returns like debt, child support or other obligations. Your federal return must be filed within three years to claim your refund or the money becomes property of the U.S. Treasury.

Penalties and interest will not be applied if you are owed a refund, however the IRS will hold your refund checks if you have not filed tax returns for 2014 and 2015.

Keep in mind you must file your 2013 tax return no later than Tuesday April 18, if you don’t file it you cannot get the refund.