NASHVILLE (AP) - As taxpayers prepare their income tax returns for 2011, the Internal Revenue Service is still holding millions that are owed to Tennessee residents from 2008.

IRS spokesman Dan Boone said the funds can't be refunded because more than 18,000 Tennesseans it should go to haven't filed returns from three years ago.

Refunds totaling $16,130,000 await 2008 filings in Tennessee. Nationally, the estimate is more than $1 billion for people who have yet to file for that year.

Boone said the late filing can still be done without penalty if a refund is owed, but only until April 17. After that, the money is turned over to the U.S. Treasury.

The IRS can still withhold refund checks for 2008 from taxpayers if they didn't file returns for 2009 and 2010.