Medicare only pays for services that are considered reasonable and necessary for the diagnosis or treatment of an illness or injury. To keep coverage decisions consistent, CMS uses:
An NCD is a nationwide decision made by CMS that tells whether Medicare will cover a specific item or service anywhere in the United States. If an NCD exists for a service, all MACs must follow it the same way in every state.
An LCD is a coverage policy written by a Medicare Administrative Contractor (MAC) for its own jurisdiction. LCDs are used when there is no NCD, or when CMS allows MACs to set additional local rules (for example, covered diagnoses, documentation requirements, or frequency limits).
In short: NCD = national rule from CMS, LCD = local rule from each MAC, but both define when Medicare will pay for a service.
A Medicare Administrative Contractor (MAC) is a private insurer that CMS hires to process Fee-For-Service (FFS) Medicare claims and apply coverage rules in a specific region. MACs are the main operational contact between Medicare and providers.
As of recent CMS data, there are 12 A/B MACs and 4 DME MACs that together process Medicare FFS claims for tens of millions of beneficiaries across the U.S.
A/B Medicare Administrative Contractors (A/B MACs) are responsible for processing Medicare Part A (facility) and Part B (professional) claims. These MACs cover hospitals, physicians, outpatient clinics, labs, SNFs, home health (Part A only), and many other provider types.
CMS divides the country into 12 A/B MAC jurisdictions. Each jurisdiction has its own MAC contractor, LCDs, Articles, audit requirements, and processing rules.
AR reps should always know their provider's MAC jurisdiction, because even the same CPT/HCPCS can have different coverage rules depending on the state.
| Jurisdiction | Contractor | States Covered |
|---|---|---|
| J-A | National Government Services (NGS) | CT, MA, ME, NH, RI, VT |
| J-B | National Government Services (NGS) | IL, MN, WI |
| J-E | Noridian Healthcare Solutions | CA, HI, NV, American Samoa, Guam |
| J-F | Noridian Healthcare Solutions | AK, AZ, ID, MT, ND, OR, SD, UT, WA, WY |
| J-H | Novitas Solutions | AR, CO, LA, MS, NM, OK, TX |
| J-J | Palmetto GBA | SC, NC, VA, WV |
| J-K | Novitas Solutions | DE, DC, MD, NJ, PA |
| J-L | First Coast Service Options (FCSO) | FL, Puerto Rico, U.S. Virgin Islands |
| J-N | WPS Government Health Administrators | IA, KS, MO, NE |
| J-S | CGS Administrators | KY, OH |
| J-15 | CGS Administrators | OH, KY (special MAC + HHH contractor) |
| J-M | Palmetto GBA | Historically handled NC/SC/VA/WV (Merged into J-J) |
A/B MACs also publish Local Coverage Determinations (LCDs) and Articles that affect your coding, documentation,
and appeals. You can look up current policies at:
🔗 medicare-coverage-database (MCD)
Durable Medical Equipment Medicare Administrative Contractors (DME MACs) are responsible for processing Medicare claims related to DMEPOS:
While A/B MACs handle hospital and physician services, DME claims are managed separately because they involve different rules, suppliers, and reimbursement structures.
Medicare divides DME claims into four regional jurisdictions, each managed by a specific MAC contractor. These jurisdictions handle:
Below is the full list of all four DME MACs, their contractors, and the states they cover.
| DME Jurisdiction | MAC Contractor | States Covered |
|---|---|---|
| Jurisdiction A | Noridian Healthcare Solutions | CT, DE, DC, ME, MD, MA, NH, NJ, NY, PA, RI, VT |
| Jurisdiction B | CGS Administrators | IL, IN, KY, MI, MN, OH, WI |
| Jurisdiction C | CGS Administrators | AL, AR, FL, GA, LA, MS, NC, NM, OK, PR, SC, TN, TX, VI |
| Jurisdiction D | Noridian Healthcare Solutions | AK, AZ, CA, CO, HI, ID, IA, KS, MO, MT, ND, NE, NV, OR, SD, UT, WA, WY, Territories |
DME suppliers must follow DME MAC-specific LCDs, documentation requirements, and prior authorization rules. Incorrect or insufficient documentation is the #1 reason for DME denials.
While Medicare has many A/B MAC jurisdictions, Home Health & Hospice (HH+H) claims are handled by a separate set of jurisdictions. These areas have different geographic boundaries than regular Part A/B MACs.
HH+H claims are processed by four specific MAC jurisdictions, each managed by a different MAC contractor:
| HH+H Jurisdiction | MAC Contractor | States Covered |
|---|---|---|
| J6 | National Government Services (NGS) | Michigan, Minnesota, Wisconsin |
| J15 | CGS Administrators | Kentucky, Ohio |
| JK | National Government Services (NGS) | Connecticut, New York, Massachusetts, Rhode Island, Vermont, New Hampshire, Maine |
| JM | Palmetto GBA | North Carolina, South Carolina, Virginia, West Virginia |
These HH+H jurisdictions are responsible for Medicare Home Health and Hospice claims only. They do not follow the same geographic mapping as A/B MACs, which is why the HH+H regions look different. Providers working with HH+H must always check which jurisdiction processes claims for their state.
The Medicare Coverage Database (MCD) is CMS’s online library of coverage policies. It includes:
AR and coding teams use MCD to confirm:
Official site: Medicare Coverage Database – mcd.cms.gov
An MCD Article is an educational or billing document published by a MAC. Articles usually:
Every document in MCD has an identifying number: