As far as I can recall FEHB plan brochures generally have defined a covered hospital as one accredited by JCAHO (“the Joint Commission”).  Until recently, the Joint Commission was the only CMS approved vendor that could accredit hospitals for Medicare participation. The AMA News reports that CMS in May 2008 approved a second vendor, DNV Healthcare.  DNV’s program is known as NIAHO.  What’s more, on October 24, CMS placed one of the Joint Commission’s programs on probation, which the Joint Commission must resolve by May 2009.