President Obama last year praised the Mayo Clinic as a "classic example" of how a health-care provider can offer "better outcomes" at lower cost. Then what should Americans think about the famous Minnesota medical center's decision to take fewer Medicare patients?

Specifically, Mayo said last week it will no longer accept Medicare patients at one of its primary care clinics in Arizona. Mayo said the decision is part of a two-year pilot program to determine if it should also drop Medicare patients at...