S&P Global Ratings has assigned its 'AAA' long-term (program) rating and 'A' underlying rating for credit program to Frost Independent School District (ISD), Texas' series 2018 general obligation (GO) unlimited-tax school building bonds. The 'AAA' program rating reflects our view of the district's eligibility for the Texas Permanent School Fund bond guarantee program. The program provides the security of a permanent fund of assets the district could use to meet debt service on bonds guaranteed by the program. (For more information on the program rating, please see our analysis of the Texas Permanent School Fund, published June 8, 2018, on RatingsDirect.) The bonds are payable from an unlimited-ad valorem tax levied on all taxable property within the district. Officials will