A bond rating assigned to an investment grade debt instrument. An AA rating reflects an opinion that that the issuer has the current capacity to meet its debt obligations and faces slightly higher solvency risk from changes in business, financial, or economic conditions than an AAA-rated instrument. Bond investors rely on bond ratings from organizations like Standard & Poor's, Moody's Investors Service, and Fitch Ratings to evaluate the default risk associated with both corporate bonds and municipal bonds. Compare to A Rating; AAA Rating; BBB Rating; Junk Bond.