Standard&Poor's Ratings Services raised its issuer credit rating (ICR) to 'AA-' from 'A+' on Massachusetts Housing Finance Agency (Mass Housing). At the same time, Standard&Poor's raised its long-term rating to 'AA-' from 'A+' on the agency's general obligation (GO) debt outstanding. The outlook is stable. The ratings are based on our view of the following strengths: Mass Housing's very strong and stable asset base, consisting of single-family and multifamily mortgage loans, Fannie Mae mortgage-backed securities (MBS), and high-quality investments; A significant reduction in the level of nonperforming assets (NPAs) over the past several years; Strong profitability ratios relative to those of similarly rated housing finance agencies (HFAs); Steadily improving equity levels, resulting in very strong leverage