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Medicare billing

How the Medicare program is structured and billed — its parts, contractors, identifiers, coverage and payment rules, and the denials specific to Medicare.

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What is Medicare billing?

Medicare billing is the work of submitting and being paid for services under Medicare, the federal health program administered by the Centers for Medicare & Medicaid Services (CMS). It has its own structure — Parts A, B, C, and D — its own contractors and identifiers, and its own coverage, payment, and appeal rules that differ from commercial billing.

This section covers how Medicare is organized and how each part is billed, the Medicare Administrative Contractors that process claims, the Medicare Beneficiary Identifier, assignment and participation, coverage determinations, the Advance Beneficiary Notice, Medicare Secondary Payer rules, and the overpayment and denial patterns that are specific to the program.

It is educational and program-specific rather than payer-agnostic marketing: Medicare's fee schedules, coverage determinations, contractor assignments, and deadlines are set by CMS and its contractors and change over time. The articles here teach the durable structure and point to the authoritative source for any figure or current rule, rather than quoting one that would go stale.

Where to start

A path from how Medicare is structured to the denials specific to it. Each article assumes the one before it; the full set continues below.

  1. Understand how Medicare is structured

    Parts A, B, C, and D — what each covers and who administers it — the frame every Medicare billing decision sits inside.

    Read: How is Medicare structured? (Parts A, B, C, D)

  2. Bill Part A

    How institutional Part A services are billed, and where Part A responsibility ends and Part B begins.

    Read: Medicare Part A billing

  3. Bill Part B

    How professional and outpatient Part B services are billed, assigned, and paid against the fee schedule.

    Read: Medicare Part B billing

  4. Understand Medicare Advantage

    Why a Part C plan is billed like a commercial payer rather than like fee-for-service Medicare, and what that changes.

    Read: Medicare Advantage (Part C) billing

  5. Use the right identifier

    The Medicare Beneficiary Identifier and why an accurate one is the first condition of a payable Medicare claim.

    Read: The Medicare Beneficiary Identifier (MBI)

  6. Reach the right contractor

    Medicare Administrative Contractors — which one processes a given claim, and why that determines local rules and where claims go.

    Read: Medicare Administrative Contractors (MACs)

Featured articles

Start here if you are new to Medicare billing.

How is Medicare structured? (Parts A, B, C, D)

A structural overview of the four parts of Medicare — Part A (hospital insurance), Part B (medical insurance), Part C (Medicare Advantage), and Part D (prescription drug coverage) — explaining how each part is administered, which claims pathway it uses, and why the distinctions matter for billing. Program rules, cost-sharing, and coverage vary by plan, jurisdiction, and effective date.

Updated · 7 min read

Medicare Part B billing

An educational overview of Medicare Part B billing: what Part B covers structurally, how professional claims are submitted to Medicare Administrative Contractors, and the enrollment, coverage, assignment, and remittance concepts that shape the process. Rules vary by contractor, service, and date; the article points to CMS as the authoritative source.

Updated · 7 min read

All articles

32 articles in this section.

Related services

The service that runs billing work like this for a practice.

Related topics

Where Medicare billing connects to the wider revenue cycle.

Related resources

Operational support for Medicare billing work.

Key terms to understand

Plain-language definitions, defined once on their glossary pages.

About this section

What does the Medicare Billing section cover?

How the Medicare program is structured (Parts A, B, C, and D) and how each is billed; the Medicare Administrative Contractors that process claims; the Medicare Beneficiary Identifier; assignment and participation; coverage determinations; the Advance Beneficiary Notice; Medicare Secondary Payer rules; overpayments and recoupment; and the denial patterns specific to Medicare. It is educational and does not state a specific fee, threshold, or contractor rule as universal.

Is Medicare Advantage billed the same as Original Medicare?

No. Original Medicare (Parts A and B) is fee-for-service, billed to a Medicare Administrative Contractor under CMS rules. Medicare Advantage (Part C) is administered by private plans that contract with Medicare, and a claim is generally billed to that plan under its own rules, networks, and prior-authorization requirements — closer to commercial billing. The section treats them separately for that reason.

Why doesn't this section list Medicare fee amounts or coverage rules?

Because they are set by CMS and its contractors and change, and much of Medicare coverage is decided locally by each contractor through coverage determinations. A fee amount or coverage rule printed here would be out of date the moment it was revised. What is durable is the structure — how the program is organized, which contractor and identifier apply, and where the current fee schedule or coverage determination is published — and that is what these articles teach.

Authoritative sources

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