Medicare Administrative Contractor Jurisdictions Map: Who Audits You and What Each MAC Reviews

Every provider and supplier that bills Original Medicare works with a Medicare Administrative Contractor, or MAC. Your MAC processes your claims, pays you, enrolls you, answers your questions, publishes local coverage determinations, handles first-level appeals, and reviews medical records for selected claims. In other words, your MAC is often the first contractor that audits you.

Knowing which MAC covers your organization matters. Each MAC publishes its own local coverage determinations, education, review topics, and Targeted Probe and Educate activities. Many providers deal with more than one MAC, for example a hospital that also operates a home health agency, or a physician group that also bills durable medical equipment.

This article explains what MACs are, how the A/B, DME, and home health and hospice jurisdictions are organized, which MAC covers each state, how provider assignment works, what MACs review, and how to stay current as contracts change. It is educational and is based on CMS information available at the time of writing. Providers should always confirm their current MAC using CMS's official maps and their MAC's website.

What Is a Medicare Administrative Contractor?

CMS defines a MAC as a private health care insurer that has been awarded a geographic jurisdiction to process Medicare Part A and Part B medical claims or durable medical equipment (DME) claims for Medicare fee-for-service beneficiaries.

According to CMS, MACs perform many activities, including:

• Processing Medicare fee-for-service claims.

• Making and accounting for fee-for-service payments.

• Enrolling providers in the fee-for-service program.

• Handling provider reimbursement services and auditing institutional provider cost reports.

• Handling redetermination requests, which are first-stage appeals.

• Responding to provider inquiries.

• Educating providers about Medicare fee-for-service billing requirements.

• Establishing local coverage determinations (LCDs).

• Reviewing medical records for selected claims.

• Coordinating with CMS and other fee-for-service contractors.

CMS reports that, in fiscal year 2024, MACs served more than 1.2 million enrolled providers, processed more than 1.1 billion fee-for-service claims, and paid about $459.7 billion in fee-for-service benefits.

How the MAC Jurisdictions Are Organized

CMS currently uses three types of MAC workloads:

• A/B MACs. CMS lists 12 A/B MAC jurisdictions that process Medicare Part A and Part B claims for their geographic areas.

• DME MACs. CMS lists four DME MAC jurisdictions that process durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) claims.

• Home Health and Hospice (HH+H) areas. Four of the A/B MACs also process home health and hospice claims. CMS notes that these HH+H areas do not match their A/B jurisdictional boundaries.

CMS publishes an A/B MAC Jurisdiction Map, an HH+H MAC Jurisdiction Map, a DME MAC Jurisdiction Map, and a MACs by State list on its Who are the MACs page.

The 12 A/B MAC Jurisdictions

The following summary is based on CMS's jurisdiction pages at the time of writing. Contract awardees can change through recompetition, so providers should confirm current information with CMS.

Jurisdiction E (JE) – Noridian Healthcare Solutions

Covers California, Hawaii, Nevada, American Samoa, Guam, and the Northern Mariana Islands.

Jurisdiction F (JF) – Noridian Healthcare Solutions

Covers Alaska, Arizona, Idaho, Montana, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. CMS posted a new award for JF to Noridian, the incumbent, in 2025.

Jurisdiction H (JH) – Novitas Solutions

Covers Arkansas, Colorado, Louisiana, Mississippi, New Mexico, Oklahoma, and Texas. On June 24, 2026, CMS announced that Novitas, the incumbent, had been awarded a new JH contract with a base period and six option years.

Jurisdiction J (JJ) – Palmetto GBA

Covers Alabama, Georgia, and Tennessee. CMS awarded the current JJ contract to Palmetto GBA in August 2024.

Jurisdiction K (JK) – National Government Services

Covers Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont for Part A and Part B. JK also processes home health and hospice claims for the New England states listed, but not New York.

Jurisdiction L (JL) – Novitas Solutions

Covers Delaware, the District of Columbia, Maryland, New Jersey, and Pennsylvania. For Part B only, JL also includes Arlington and Fairfax counties and the City of Alexandria in Virginia.

Jurisdiction M (JM) – Palmetto GBA

Covers North Carolina, South Carolina, Virginia, and West Virginia, except that for Part B, Arlington and Fairfax counties and the City of Alexandria in Virginia are served by JL. JM also processes home health and hospice claims for a large group of southern and midwestern states.

Jurisdiction N (JN) – First Coast Service Options

Covers Florida, Puerto Rico, and the U.S. Virgin Islands.

Jurisdiction 5 (J5) – Wisconsin Physicians Service

Covers Iowa, Kansas, Missouri, and Nebraska.

Jurisdiction 6 (J6) – National Government Services

Covers Illinois, Minnesota, and Wisconsin for Part A and Part B. J6 also processes home health and hospice claims for a large group of western and other states and territories.

Jurisdiction 8 (J8) – Wisconsin Physicians Service

Covers Indiana and Michigan.

Jurisdiction 15 (J15) – CGS Administrators

Covers Kentucky and Ohio for Part A and Part B. J15 also processes home health and hospice claims for a group of central and mid-Atlantic states.

The Four Home Health and Hospice Areas

Home health agencies and hospices are served by one of four A/B MACs that also process HH+H claims. According to CMS's jurisdiction pages:

• Jurisdiction 6 (National Government Services) processes HH+H claims for Alaska, American Samoa, Arizona, California, Guam, Hawaii, Idaho, Michigan, Minnesota, Nevada, New Jersey, New York, the Northern Mariana Islands, Oregon, Puerto Rico, the U.S. Virgin Islands, Washington, and Wisconsin.

• Jurisdiction K (National Government Services) processes HH+H claims for Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.

• Jurisdiction 15 (CGS Administrators) processes HH+H claims for Colorado, Delaware, the District of Columbia, Iowa, Kansas, Maryland, Missouri, Montana, Nebraska, North Dakota, Pennsylvania, South Dakota, Utah, Virginia, West Virginia, and Wyoming.

• Jurisdiction M (Palmetto GBA) processes HH+H claims for Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Kentucky, Louisiana, Mississippi, New Mexico, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, and Texas.

This means a home health agency or hospice may have a different MAC for its home health and hospice claims than a hospital or physician in the same state. For example, a hospice in Illinois sends hospice claims to Palmetto GBA (JM), while Illinois hospitals and physicians bill National Government Services (J6).

The Four DME MAC Jurisdictions

DMEPOS suppliers bill one of four DME MACs, based on CMS rules. According to CMS's jurisdiction pages:

• DME MAC Jurisdiction A (Noridian Healthcare Solutions) serves the northeastern states, including Connecticut, Delaware, the District of Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. CMS awarded the current JA contract to Noridian in February 2025.

• DME MAC Jurisdiction B (CGS Administrators) serves Illinois, Indiana, Kentucky, Michigan, Minnesota, Ohio, and Wisconsin.

• DME MAC Jurisdiction C (CGS Administrators) serves Alabama, Arkansas, Colorado, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, the U.S. Virgin Islands, Virginia, and West Virginia.

• DME MAC Jurisdiction D (Noridian Healthcare Solutions) serves Alaska, American Samoa, Arizona, California, Guam, Hawaii, Idaho, Iowa, Kansas, Missouri, Montana, Nebraska, Nevada, North Dakota, the Northern Mariana Islands, Oregon, South Dakota, Utah, Washington, and Wyoming.

For DMEPOS claims, the jurisdiction is generally determined by the beneficiary's permanent residence, not the supplier's location. Suppliers serving beneficiaries in multiple regions may therefore work with more than one DME MAC.

How Providers Are Assigned to MACs

CMS has defined rules for assigning providers, physicians, and suppliers to MACs:

• A/B and HH+H rule. Providers are generally assigned to the MAC that covers the state where they are located. Home health agencies and hospices are assigned to the HH+H MAC for their state.

• DMEPOS rule. DMEPOS claims are generally processed by the DME MAC for the beneficiary's state of residence.

• Specialty providers and demonstrations. Some specialty provider types and demonstrations may be assigned to particular MACs.

• Qualified chains. CMS has rules that may allow qualified provider chains to request assignment to a single MAC under certain conditions.

Some services can be billed to either an A/B MAC or a DME MAC depending on the item and setting. CMS's Claims Processing Manual explains how jurisdiction is determined for certain DMEPOS items, and CMS issues periodic updates on which codes are processed by DME MACs, A/B MACs, or both.

What Each MAC Reviews

All MACs perform medical review as part of their responsibilities, but each MAC selects its own focus areas based on data analysis and local risks. MAC medical review activities include:

Prepayment and Postpayment Review

MACs can review claims before payment (prepayment) or after payment (postpayment) by requesting additional documentation through Additional Documentation Requests (ADRs). Providers generally have 45 days to respond to MAC ADRs.

Targeted Probe and Educate (TPE)

Under TPE, MACs select providers with high claim error rates or unusual billing practices for review of a small sample of claims, followed by one-on-one education. Providers may go through up to three rounds of review and education. Continued high error rates after three rounds may result in referral to CMS for further action.

Service-Specific Reviews

MACs publish lists of topics under review, often focused on services with high improper payment rates in their jurisdiction. These may include specific procedures, inpatient admissions, therapy services, home health episodes, hospice eligibility, or DMEPOS items.

Local Coverage Determinations

MACs establish LCDs and billing and coding articles that define coverage and documentation requirements for specific services in their jurisdictions. Because LCDs can vary by MAC, a service may have different documentation requirements depending on where the provider is located.

Prior Authorization and Pre-Claim Review

MACs administer CMS prior authorization and pre-claim review programs for certain services, such as specified hospital outpatient department services, certain DMEPOS items, and, in some states, home health services under the Review Choice Demonstration.

Cost Report Audits

For institutional providers, MACs audit cost reports to determine final reimbursement.

Appeals

MACs handle redeterminations, the first level of Medicare fee-for-service appeals, including appeals of denials resulting from MAC review and from other contractors' findings recovered through the MAC.

How MACs Work With Other Contractors

MACs are not the only contractors that review claims. They coordinate with:

• Recovery Audit Contractors (RACs), which identify improper payments after payment. MACs adjust claims and recover overpayments identified by RACs.

• The Supplemental Medical Review Contractor (SMRC), which conducts nationwide project-based reviews. MACs adjust claims and recover overpayments identified by the SMRC.

• The Comprehensive Error Rate Testing (CERT) contractor, which measures the improper payment rate. MACs recoup overpayments identified through CERT.

• Unified Program Integrity Contractors (UPICs), which investigate potential fraud, waste, and abuse. MACs may refer providers to UPICs and implement payment suspensions and other actions.

Because MACs process recoveries for other contractors, providers should watch MAC communications, remittance advice, and demand letters closely after any external review.

MAC Contracts and Transitions

CMS awards MAC contracts through competitive procurements. Recent contracts generally include a base period and multiple option years. CMS jurisdiction pages list the contract awardee, award date, and anticipated contract end date for each jurisdiction. When a contract is recompeted, the incumbent may win again or a new contractor may take over the workload.

When a MAC changes, providers may need to:

• Set up new portal accounts and electronic data interchange (EDI) connections.

• Update addresses for claims, correspondence, and appeals.

• Review the new MAC's LCDs and articles, which may differ from the previous MAC's policies.

• Track the transition schedule for pending claims, appeals, and medical review.

• Confirm that electronic funds transfer and remittance arrangements continue without interruption.

Even when the incumbent wins, as in recent awards for Jurisdiction F and Jurisdiction H, providers should watch for updates to systems, processes, and contact information.

How to Find and Confirm Your MAC

• Use CMS's Who are the MACs page, which links to the A/B, HH+H, and DME MAC jurisdiction maps and the MACs by State list.

• Check the CMS jurisdiction page for your MAC to see the contract awardee, states served, and anticipated contract end date.

• Review your remittance advice and enrollment records, which identify the contractor processing your claims.

• Confirm through your MAC's website and provider portal.

Examples: Which MACs Does Your Organization Use?

Because the A/B, HH+H, and DME jurisdictions do not line up, many organizations work with more than one MAC. The following hypothetical examples, based on the CMS jurisdiction information above, show how this plays out.

A Health System in Illinois

An Illinois hospital and its employed physicians bill National Government Services under Jurisdiction 6. If the health system also owns a home health agency and a hospice in Illinois, those claims go to Palmetto GBA under Jurisdiction M. If it operates a DMEPOS supplier that serves Illinois residents, those claims go to CGS Administrators under DME MAC Jurisdiction B. That is three different MACs, each with its own portal, review topics, and education.

A Hospice in Pennsylvania

Pennsylvania hospitals and physicians bill Novitas Solutions under Jurisdiction L. A Pennsylvania hospice, however, submits hospice claims to CGS Administrators under Jurisdiction 15. Its staff must follow CGS's hospice education and review activities, not Novitas's.

A DMEPOS Supplier Serving Several States

A supplier located in Missouri that ships items to beneficiaries in Missouri, Illinois, and Arkansas generally bills the DME MAC for each beneficiary's state of residence. That could mean Noridian for Missouri residents (DME Jurisdiction D), CGS for Illinois residents (DME Jurisdiction B), and CGS for Arkansas residents (DME Jurisdiction C).

A Physician Group in Northern Virginia

A physician group in Fairfax County, Virginia, bills Part B services to Novitas under Jurisdiction L, while a group in Richmond bills Palmetto GBA under Jurisdiction M. Hospitals throughout Virginia bill Part A to Palmetto GBA under Jurisdiction M.

Responding to a MAC Review Request

When your MAC sends an Additional Documentation Request or a TPE notification, a consistent process helps:

• Log the request, including the contractor, claims, documents requested, and deadline.

• Confirm that the request came from your MAC by checking the contractor name and contact information against CMS and MAC websites.

• Identify the applicable coverage requirements, including any LCDs and billing and coding articles from your MAC.

• Gather complete records, including documentation from ordering or referring providers when required.

• Review the records for completeness, signatures, and legibility before submission.

• Submit using an accepted method, such as esMD or the MAC's portal, and keep proof of submission.

• Track results, attend any TPE education session, and implement corrective actions.

• Calendar appeal deadlines if claims are denied.

Using MAC Resources to Reduce Audit Risk

Each MAC publishes resources that can help providers reduce errors before claims are reviewed:

• Medical review results and common error summaries, which show what reviewers are finding.

• Provider education webinars and workshops on specific services.

• Documentation checklists and coverage summaries for frequently reviewed services.

• Self-service portal tools for checking claim status, eligibility, and ADRs.

• Contact centers and provider outreach teams that answer billing and policy questions.

Reviewing these resources regularly, especially for services that represent a large share of your Medicare revenue, can help you find and fix problems before your MAC selects your claims for review.

Building MAC Awareness Into Your Compliance Program

• Identify every MAC your organization works with, including A/B, HH+H, and DME MACs.

• Subscribe to each MAC's email updates and newsletters.

• Monitor each MAC's list of medical review topics and TPE activities.

• Track LCDs and billing and coding articles that apply to your services.

• Review MAC education materials and webinars on common errors.

• Maintain a central log of all ADRs, TPE letters, and demand letters from each MAC.

• Watch for contract transitions and update systems and contacts as needed.

Common Mistakes Providers Make With MACs

• Assuming a home health agency or hospice uses the same MAC as a hospital or physician in the same state.

• Using LCDs from the wrong MAC.

• Missing ADRs because portal or mailing addresses are outdated.

• Ignoring MAC review topic announcements.

• Failing to prepare for a MAC contract transition.

• Not realizing that overpayments identified by other contractors are recovered through the MAC.

Frequently Asked Questions

How many MACs are there?

CMS lists 12 A/B MAC jurisdictions and four DME MAC jurisdictions. Four of the A/B MACs also process home health and hospice claims.

How do I know which MAC covers me?

Use CMS's Who are the MACs page and the MACs by State list, and confirm with your MAC's website.

Why does my hospice have a different MAC than my hospital?

CMS assigns home health and hospice claims to four HH+H areas whose boundaries do not match the A/B MAC jurisdictions.

Which DME MAC processes my supplier claims?

DMEPOS claims are generally processed by the DME MAC for the beneficiary's state of residence.

Do MACs audit providers?

Yes. MACs review medical records for selected claims through prepayment and postpayment review, Targeted Probe and Educate, and other programs. They also audit institutional cost reports.

Conclusion

Your Medicare Administrative Contractor is one of the most important organizations in your Medicare relationship. It pays your claims, sets local coverage policies, reviews your documentation, handles your first-level appeals, and recovers overpayments identified by other contractors. Knowing which A/B, home health and hospice, and DME MACs serve your organization, what each one is reviewing, and how contract changes may affect you helps you stay compliant and respond effectively when an audit request arrives.

How HealthBridge Can Help

HealthBridge is a healthcare management consulting firm that helps providers identify their MACs, monitor MAC medical review and TPE activities, interpret LCDs, respond to ADRs, prepare appeals, and prepare for MAC transitions. If you would like help understanding which MAC audits you and what it is reviewing, please get in touch with us. We will be happy to help you with this topic.

References

• Centers for Medicare & Medicaid Services. What's a MAC. https://www.cms.gov/medicare/coding-billing/medicare-administrative-contractors-macs/whats-mac

• Centers for Medicare & Medicaid Services. Who are the MACs. https://www.cms.gov/medicare/coding-billing/medicare-administrative-contractors-macs/who-are-macs

• Centers for Medicare & Medicaid Services. Provider Assignment. https://www.cms.gov/medicare/coding-billing/medicare-administrative-contractors-macs/provider-assignment

• Centers for Medicare & Medicaid Services. MACs: What's New. https://www.cms.gov/medicare/coding-billing/medicare-administrative-contractors-macs/whats-new

• Centers for Medicare & Medicaid Services. A/B MAC Jurisdiction Map. https://www.cms.gov/files/document/ab-jurisdiction-map03282023pdf.pdf

• Centers for Medicare & Medicaid Services. HH+H MAC Jurisdiction Map. https://www.cms.gov/files/document/hhh-jurisdiction-map03282023pdf.pdf-0

• Centers for Medicare & Medicaid Services. DME MAC Jurisdiction Map. https://www.cms.gov/files/document/dme-jurisdiction-map03282023pdf.pdf-0

• Centers for Medicare & Medicaid Services. MACs by State. https://www.cms.gov/files/document/macs-state03282023pdf.pdf

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction 6 (J6). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-6-j6

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction 15 (J15). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-15-j15

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction K (JK). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-k-jk

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction M (JM). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-m-jm

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction L (JL). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-l-jl

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction N (JN). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-n-jn

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction E (JE). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-e-je

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction 5 (J5). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-5-j5

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction 8 (J8). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-8-j8

• Centers for Medicare & Medicaid Services. Who are the MACs: A/B MAC Jurisdiction J (JJ). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-a-b-mac-jurisdiction-j-jj

• Centers for Medicare & Medicaid Services. Jurisdiction H Award Fact Sheet (June 2026). https://www.cms.gov/files/document/jurisdiction-h-award-fact-sheet-june-2026.pdf

• Centers for Medicare & Medicaid Services. Jurisdiction F Award Fact Sheet (August 2025). https://www.cms.gov/files/document/jf-mac-award-fact-sheet-08192025.pdf

• Centers for Medicare & Medicaid Services. DME MAC Jurisdiction A Award Fact Sheet (2025). https://www.cms.gov/files/document/ja-2025-award-fact-sheet.pdf

• Centers for Medicare & Medicaid Services. Who are the MACs: DME MAC Jurisdiction B (JB). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-dme-mac-jurisdiction-b-jb

• Centers for Medicare & Medicaid Services. Who are the MACs: DME MAC Jurisdiction C (JC). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-dme-mac-jurisdiction-c-jc

• Centers for Medicare & Medicaid Services. Who are the MACs: DME MAC Jurisdiction D (JD). https://www.cms.gov/medicare/medicare-contracting/medicare-administrative-contractors/who-are-the-macs-dme-mac-jurisdiction-d-jd

• Centers for Medicare & Medicaid Services. Medicare Claims Processing Manual, Chapter 20, Durable Medical Equipment, Prosthetics, Orthotics, and Supplies. https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c20.pdf

• Centers for Medicare & Medicaid Services. Medicare Program Integrity Manual, Chapter 3. https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/pim83c03.pdf