Standard&Poor's Ratings Services raised its 'AA+' and 'AA+/A-1+' ratings to 'AAA' and 'AAA/A-1+', respectively, on the Iowa Finance Authority's (IFA) single-family mortgage revenue bonds. At the same time, we assigned our 'AAA' long-term rating to the IFA's series 2016A and C single-family mortgage revenue bonds. The outlook is stable. Finally, Standard&Poor's assigned its 'AAA/A-1+' rating to the authority's series 2016B single-family mortgage revenue bonds. The 'AAA' long-term component of the rating on the 2016B bonds is based on the long-term rating on the bond indenture. The 'A-1+' short-term component of the rating on the 2016B bonds reflects an enhancement in the form of a standby-bond purchase agreement (SBPA) from Federal Home Loan Bank of Des Moines