Moody's Ratings and S&P Ratings

Below is the Minicipal Bond ratings table which shows Moody's ratings and S&P ratings for municipal bonds.

Ratings	Provider	Description
Aaa	Moody's ratings	Judged to be of the best quality.
AAA	S&P ratings	Carry the smallest degree of investment risk. Interest payments are protected by a large or exceptionally stable margin; principal is secure.
Aa	Moody's ratings	Judged to be high quality by all standards. Together with the "Aaa" group, "Aa" bonds comprise what are generally known as high grade bonds. "Aa" bonds are rated lower because margins of protection may not be as large as in "Aaa" securities, or other elements may make the long-term risk appear somewhat greater than in "Aaa" securities.
AA	S&P ratings	Have a very strong capacity to pay interest and repay principal. Differ from the highest-rated issues only in a small degree.
A	Moody's ratings	Possess many favorable investment attributes; considered an upper-medium grade obligation. Factors giving security to principal and interest are considered adequate, but some elements suggest a susceptibility to impairment in the future.
a	S&P ratings	Have a strong capacity to pay interest and repay principal, although they may be somewhat more susceptible to adverse effects of changes in circumstances and economic conditions.
Baa	Moody's ratings	Considered medium grade - neither highly protected nor poorly secured. Interest payments and principal security appear adequate for the present, but certain protective elements may be lacking or characteristically unreliable over time. Have no outstanding investment characteristics; may have speculative characteristics.
BBB	S&P ratings	Normally, have adequate capacity to pay interest and repay principal, but are more likely to have those capacities weakened during adverse economic conditions or changing circumstances than debt in higher-rated categories.