Egan-Jones is downgrading its rating on U.S. debt to AA- from AA, citing Federal Reserve plans to try to stimulate the economy.
The credit rating agency says the Fed's plans to buy mortgage bonds will likely hurt the economy more than help it. Egan-Jones says the plan will reduce the value of the dollar and raise the price of oil and other commodities, hurting businesses and consumers.
It is the second downgrade of the U.S. by the company. In April, Egan-Jones downgraded the U.S. to AA from AA+. The company stripped the U.S. of a top AAA rating in July 2011.
On Thursday, the Fed said it would buy $40 billion of mortgage bonds a month to help the economic recovery.