Bobert

Rules for administering both Medicare and Medicaid are set up by the individual states, theoretically meeting the minimum requirements of the Federal law; but for both there are "a few" organizations that operate in several states, so the "management agencies" may be the same in several states, but they have to operate according to the rules set up by the state where the insured person lives. The "administrative rules" within an individual state, and sometimes in different parts of the same state can vary by quite a bit.

Federal Social Security Benefits are paid directly by the Fed, but so far as I've been able to figure it, all medical benefits are handled by the states (or by their hired guns).

For complete confusion, you might find some fairly believeable statistics on the variations between areas in Medpac Report to Congress for 2012, although since it's written for Congress it may be mostly unintelligible to cogent humans. (The report is actually intended to tell "how well it's working" rather than "how it works," - if that distinction makes any sense to you.)

John