The Mayo Clinic stopped accepting Medicare patients on Jan 1 at one of its primary-care clinics in Arizona, saying the U.S. government pays too little. More than 3,000 patients eligible for Medicare will be forced to pay cash if they want to continue seeing their doctors at a Mayo family clinic in Glendale, AZ. The Mayo organization had 3,700 staff physicians and scientists and treated 526,000 patients in 2008. It lost $840 million last year on Medicare, a Mayo spokesman said.