The following is from Standard & Poor's...
On Aug. 5, 2011, Standard & Poor's Ratings Services lowered its long-term sovereign credit rating on the United States of America to 'AA+' from 'AAA'. The outlook on the long-term rating is negative. At the same time, Standard & Poor's affirmed its 'A-1+' short-term rating on the U.S. In addition, Standard & Poor's removed both ratings from CreditWatch, where they were placed on July 14, 2011, with negative implications.
The transfer and convertibility (T&C) assessment of the U.S. -- our assessment of the likelihood of official interference in the ability of U.S.-based public- and private-sector issuers to secure foreign exchange for debt service -- remains 'AAA'.
United States of America Long-Term Rating Lowered To 'AA+' On Political Risks And Rising Debt Burden; Outlook Negative