SSI ratios for the FY 2010 Medicare DSH calculation were published on September 11, 2012. According to our calculations, the average change in providers’ SSI ratios from FY 2009 is a decrease of approximately 0.0005 for FY 2010. These FY 2010 ratios have been corrected from an earlier version that was published and summarily removed from the CMS website in May 2012. Of 3541 IPPS hospitals on the list, 3324 hospitals (almost 94 percent) have seen an increase from the previously published numbers for FY 2010; 136 have experienced no change; 81 hospitals’ SSI ratios have decreased.

According to information published on the CMS website, the methodology used to calculate the FY 2010 ratios is the same methodology used to calculate the FY 2006 to 2009 ratios: Medicare Advantage patient days were included in the ratios and the ratios were calculated in accordance with Ruling CMS-1498-R, which requires inclusion of Part A exhausted benefit days in both the numerator and denominator of the SSI fraction and inclusion of all labor and delivery room inpatient days that meet the requirements for inclusion, regardless of whether the patient had first occupied a routine care bed. See CMS-1498-R, available by clicking here. The IPPS SSI ratios are available by clicking here. The IRF SSI ratios are available by clicking here.