S&P Global Ratings assigned its 'AAA' rating to Iowa Finance Authority's (IFA) series 2017C single-family mortgage revenue bonds. At the same time, we assigned our 'AAA/A-1+' rating to the authority's series 2017D single-family mortgage revenue bonds. We also affirmed our 'AAA' rating and 'AAA/A-1+' rating on the authority's existing single-family mortgage revenue debt. The outlook on all ratings is stable. The 'AAA' long-term component of the rating on the 2017D bonds is based on the long-term rating on the bond indenture. The 'A-1+' short-term component of the rating on the 2017D bonds reflects an enhancement in the form of a standby-bond purchase agreement (SBPA) from Federal Home Loan Bank of Des Moines, and our opinion of the likelihood that bondholders