Senior citizens seeking treatment from the Mayo clinics in Arizona will have to pay out of their own pockets from now on. Mayo announced last week that its Arizona facilities would no longer accept Medicare patients. Mayo’s Arizona facilities lost $120 million treating Medicare patients last year, and Mayo lost $840 million nationwide on Medicare patients.

This is that outfit that President Obama pointed to as a model for the entire health care system. In September, he praised Mayo for having “the best quality and the lowest cost of just about any system in the country.”

Mayo is hardly the first provider to drop Medicare patients because the program’s reimbursement rates are too low. According to a 2008 report by the Medicare payment advisory commission, 29 percent of Medicare beneficiaries have trouble finding a primary care doctor willing to treat them.

But seniors’ access to health care could get worse: The Senate health care bill cuts $493 billion from Medicare over the next 10 years, and the government agency charged with running the program has warned: “providers for whom Medicare constitutes a substantive portion of their business could find it difficult to remain profitable and … might end their participation in the program (possibly jeopardizing access to care for beneficiaries).”

(Most of the information in this post comes from Jeff Jacoby’s excellent column today at the Boston Globe.)