35-324. Investment of trust funds The treasurer shall invest and reinvest monies of trust funds in: 1. Any securities allowed for the investment of public monies. 2. Fixed income securities of corporations organized and doing business in any state of the United States or the District of Columbia that carry one of the two highest ratings of Moody's investors service and Standard and Poor's rating service or their successors. If only one of these services rates the security, it must carry the highest rating of that service. If a rating change occurs after purchase, it is not mandatory to sell the security.
Arizona Legal Code