expensive testing equipment, inpatient beds, and specialists has been the key to cost containment in successful single payer systems. Adopting a Blue Cross or other private insurer's benefits package would be a serious error.  Our studies (together with Elizabeth Warren) have found that three quarters of those bankrupted by illness or medical bills were privately insured.  Since Blue Cross was the dominant insurer in several of the states we have studied, it is clear that its benefit package left a very large number of its enrollees vulnerable to medical bankruptcy. Medicare also provides a simple model for the enrollment process.  It uses the Social Security records to identify all eligible persons.  Since Social Security maintains current addresses for registered individual, gleaning a list of the vast majority of state residents eligible for a state single payer system should be simple, leaving only the task of enrolling the relatively small number of individuals without Social Security numbers. Paying providers should also be simple if a single payer plan is properly structured, and here too Medicare provides much of the needed infrastructure.  Medicare has collected detailed financial data for decades from every hospital, home care agency and dialysis center.  Hence, determining these institutions global budgets should be a fairly simple matter.  Virtually every outpatient fee-for-service provider also has a UPIN number.  Of course, Medicare also has an extensive infrastructure for disbursing payments to fee-for-service providers.  So the only substantive administrative task needed to implement a single payer system on the outpatient side