The Justice Department says in a statement issued Wednesday that Issac Lanier Avant failed to file timely returns between 2008 and 2013 despite earning more than $165,000 annually.
The website Legistorm lists Avant's position as chief of staff to Rep. Bennie Thompson of Mississippi. Thompson's office did not immediately respond to a request for comment.
The Justice Department says Avant filed returns in 2006 and 2007, but those filings each contained false deductions.
Sentencing is scheduled in January. Avant faces a statutory maximum sentence of one year in prison. As part of his plea agreement, Avant has agreed to pay a restitution of more than $153,000 to the IRS.
Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.