On July 28, 2008, WLF filed formal comments with the Centers for Medicare and Medicaid Services (CMS), urging the agency to amend its Stark Law regulations to specifically address physician-owned implant and other medical device companies (POCs). WLF urged CMS to make clear that POCs are subject to the Stark Law’s prohibitions against physician self-referral. The Stark Law bars doctors from referring their Medicare and Medicaid patients to medical services companies (such as labs that perform medical tests) in which the doctor holds an ownership interest. WLF said that some doctors have ownership interests in POCs, which generally provide no added medical benefits but rather simply serve as an additional layer in the distribution chain — thereby needlessly driving up costs. WLF urged CMS to rule that doctors violate the Stark Law when they use their leverage to pressure hospitals to make purchases from POCs.