"It has been a tremendous privilege to serve the people of Utah during my time in the United States House of Representatives, but my time in the House should not be the sum total of my service. Today, I am announcing that I will not seek reelection to the House of Representatives," he said.
Matheson sits in the most conservative House seat in the country held by a Democrat. He survived against odds in 2012, defeating Republican Mia Love by a slim margin.
Love, the mayor of Saratoga Springs and a highly touted Republican recruit, is running again in 2014. She is seeking to become the first black woman Republican elected to Congress. In a statement reacting to Matheson's announcement, Love said her focus is unchanged.
"Congressman Matheson has served our state with passion and has been a dedicated public servant during his tenure in Congress, she said. "His announcement today does not change my campaign to represent the people of Utah’s 4th congressional district. I wish Congressman Matheson the very best during his final year as Congressman."
Mitt Romney carried 67 percent of Matheson's 4th district in 2012, illustrating how difficult it will be for Democrats to compete there. The son of a former governor, Matheson had cultivated a conservative profile over the years that allowed him to survive. He's often broken ranks with his party. For example, he voted with Republicans earlier this year for a spending bill that would strip funding from the federal health-care law.
"My colleagues and I will miss Jim’s voice, but we offer him our best wishes as he and his family start the next chapter of their service to the people of Utah," said Democratic Congressional Campaign Committee Chairman Steve Israel (N.Y.) in a statement.
National Republican Congressional Committee Chairman Greg Walden (Ore.) called Matheson's decision a "warning signal" for Democrats.
"Not only will this announcement allow Republicans to focus our energy and resources on defeating other vulnerable Democrats, but it also proves that ObamaCare has become a total nightmare for any Democrat running in 2014," he said in a statement.
President Obama thanked Matheson for his service.
"He has been a forceful advocate of our nation’s veterans and worked to strengthen our economy through his support of key trade agreements," Obama said in a statement.
Matheson was first elected in 2000. He is a former co-chair of the Blue Dog Coalition, a group of conservative House Democrats whose ranks have have been shrinking in recent years.
He becomes the first House Democrat to announce his retirement in 2014. Eight Republicans have said they are stepping down, including Rep. Frank Wolf (R-Va.), who announced his retirement earlier Tuesday afternoon.
Updated at 6:24 p.m.