Providers talk about "billing Medicare" as though Medicare were a single desk. It is not. Medicare sets national rules and then contracts the actual work — processing, paying, and hearing the first level of appeal — to a set of private companies operating in defined geographic jurisdictions.
These are Medicare Administrative Contractors, and there are roughly a dozen covering the country. Novitas, Palmetto GBA, Noridian, WPS, National Government Services, CGS, First Coast. Your state belongs to exactly one of them for Part B.
Why the distinction is practical, not trivia
Three things follow from which contractor covers you.
They decide your appeal. A redetermination — the first level — is heard by the same contractor that denied the claim. Knowing who they are and how they read a particular policy is not administrative color; it is the substance of whether an appeal succeeds.
They write local coverage determinations. National coverage determinations set the floor, and local determinations fill the very large gaps between them. This is why identical care is covered in one state and denied in another with no change in national policy. If you have ever been told "that is covered in our other office," this is usually why.
Their policies travel across their jurisdiction. A contractor covers several states, so an appeal argument that works in one usually works in all of them. If you operate across state lines, knowing which of your locations share a contractor tells you where your existing knowledge transfers and where it does not.
What to do with this
Know your contractor by name. When a Medicare denial arrives, check whether a local coverage determination governs it before writing an appeal on clinical grounds — arguing medical necessity against an explicit local policy is a losing posture, and the winning argument is usually that the policy is satisfied rather than that it should not apply.
Denials Piling Up?
We handle the revenue cycle end to end — coding by certified coders, claim submission, denial management and appeals, and A/R follow-up, with six reported numbers every month.