Change in rule will help only some HHA ownership transitions. Background: Under regulations that took effect Jan. 1, an agency that has undergone a change of ownership (CHOW) in the last 36 months will suffer a Medicare billing deactivation if there is a second CHOW. The deactivation can only be remedied with a state or deemed accreditation survey, the Centers for Medicare & Medicaid Services said in Dec. 18, 2009 Transmittal No. 318 (CR 6750). Due to a wider than usual definition of a CHOW, the change could wreak major havoc on agencies that simply go through minor stock or ownership partner changes (see Eli's HCW, Vol. XIX, No. 2, p. 10). But the National Association for Home Care & Hospice expects CMS to issue new guidance saying that the 36-month rule will apply to full changes in ownership only, it tells members. The punishing rule will still affect agency mergers and acquisitions, industry observers expect.