DEFINITION of 'AA+/Aa1'
The highest rating that some ratings agencies assign to a security or insurance carrier. This rating signifies that there is little to no risk of default and is often assigned to securities that have AMBAC or another type of insurance backing. Investors or policyholders can rest assured that their money is secure with this rating.
BREAKING DOWN 'AA+/Aa1'
The ratings assigned by the various ratings agencies are based primarily upon the insurer's or issuer's creditworthiness. This rating can therefore be interpreted as a direct measure of the probability of default. However, credit stability and priority of payment are also factored into the rating.