Mayo said it will continue to accept Medicare for critical care and specialty services as well as lab services and physical therapy—but not routine primary care.
Over 50% of their practice is taking care of Medicare patients. Primary care is a small component of their practice, so apparently that is why Mayo decided to pull back on primary care, while continuing to provide critical care.
http://takingnote.tcf.org/2009/10/ma...-patients.html