Insurance Identifier Lookup MAA – MZZ
| Prefix | Plan Name |
|---|---|
| M2C | Blue Cross Blue Shield of Illinois |
| M2D | Blue Cross Blue Shield of Illinois |
| M2E | Blue Cross Blue Shield of Texas |
| M2F | Blue Cross Blue Shield of Texas |
| M2G | Blue Cross Blue Shield of Texas |
| M2H | Regence Blue Cross Blue Shield of Oregon |
| M2I | BCBS of Western New York |
| M2J | Blue Cross Blue Shield of Illinois |
| M2K | BCBS of Arizona |
| M2L | Blue Cross Blue Shield of Massachusetts |
| M2N | Anthem BCBS of Wisconsin |
| M2P | Regence Blue Cross Blue Shield of Oregon |
| M2Q | Anthem BCBS of Wisconsin |
| M2R | Blue Cross Blue Shield of Texas |
| M2S | Blue Cross Blue Shield of Illinois |
| M2T | Regence Blue Cross Blue Shield of Oregon |
| M2U | Anthem BCBS of Wisconsin |
| M2V | BCBS if Arizona |
| M2W | Blue Cross Blue Shield of Rhode Island |
| M2X | Blue Cross Blue Shield of Illinois |
| M2Y | Regence Blue Cross Blue Shield of Oregon |
| M3A | BCBS of Kansas |
| M3B | BCBS of Western New York |
| M3C | Blue Cross Blue Shield of Rhode Island |
| M3D | Regence Blue Cross Blue Shield of Oregon |
| M3E | Blue Cross Blue Shield of Illinois |
| M3F | Blue Cross Blue Shield of Texas |
| M3G | Blue Cross Blue Shield of Rhode Island |
| M3H | Blue Cross Blue Shield of Minnesota |
| M3J | Empire Blue Cross Blue Shield |
| M3K | Anthem BCBS of Wisconsin |
| M3L | Blue Cross Blue Shield of Michigan |
| M3M | Regence Blue Cross Blue Shield of Oregon |
| M3P | BCBS of Arizona |
| M3R | Blue Cross Blue Shield of Texas |
| M3S | Blue Cross Blue Shield of Illinois |
| M3T | Anthem BCBS of Georgia |
| M3U | Anthem BCBS of Indiana |
| M3V | BCBS of Arizona |
| M3W | Regence Blue Cross Blue Shield of Oregon |
| M3X | Anthem BCBS of Wisconsin |
| M3Y | Anthem BCBS of Georgia |
| M3Z | Anthem BCBS of Georgia |
| M4A | Highmark BCBS of Pennsylvania |
| M4B | Highmark BCBS of Pennsylvania |
| M4C | Anthem BCBS of Kentucky |
| M4D | Regence Blue Cross Blue Shield of Oregon |
| M4F | Blue Cross Blue Shield of Texas |
| M4G | Anthem BCBS of Virginia |
| M4H | Anthem BCBS of Missouri |
| M4L | Highmark BCBS of Pennsylvania |
| M4M | Anthem BCBS of Missouri |
| M4N | Anthem BCBS of Virginia |
| M4P | Blue Cross Blue Shield of Texas |
| M4Q | Blue Cross Blue Shield of Michigan |
| M4R | Blue Shield of Northeastern New York |
| M4S | Blue Cross Blue Shield of Illinois |
| M4T | Regence Blue Cross Blue Shield of Oregon |
| M4U | Blue Cross Blue Shield of Minnesota |
| M4Y | Blue Cross of Idaho |
| M5A | Blue Cross Blue Shield of Minnesota |
| M5C | Anthem BCBS of Missouri |
| M5D | Anthem BCBS of Missouri |
| M5E | Anthem BCBS of Missouri |
| M5F | Blue Cross Blue Shield of Texas |
| M5K | Blue Cross Blue Shield of Illinois |
| M5M | Blue Cross Blue Shield of Texas |
| M5R | BCBS of Western New York |
| M5X | Blue Cross Blue Shield of Illinois |
| M6A | Blue Cross Blue Shield of Texas |
| M6C | Empire Blue Cross Blue Shield |
| M6F | Blue Cross Blue Shield of Texas |
| M6S | Blue Cross Blue Shield of Illinois |
| M6U | Anthem BCBS of Ohio |
| M7A | Blue Cross of California |
| M7B | Premera Blue Cross |
| M7C | Empire Blue Cross Blue Shield |
| M7D | Blue Cross Blue Shield of North Dakota |
| M7E | Blue Cross of California |
| M7F | Blue Cross Blue Shield of Texas |
| M7M | Anthem BCBS of Colorado |
| M7S | Blue Cross Blue Shield of Illinois |
| M7V | Anthem BCBS of Missouri |
| M7W | Anthem BCBS of Indiana |
| M7X | Anthem BCBS of Kentucky |
| M8A | Anthem BCBS of Colorado |
| M8F | Blue Cross Blue Shield of Texas |
| M8H | Empire Blue Cross Blue Shield |
| M8S | Blue Cross Blue Shield of Illinois |
| M8W | Anthem BCBS of Maine |
| M8X | Anthem BCBS of New Hampshire |
| M8Z | Unassigned Prefix |
| M9A | Empire Blue Cross Blue Shield |
| M9C | Empire Blue Cross Blue Shield |
| M9F | Blue Cross Blue Shield of Texas |
| M9N | Blue Cross of California |
| M9S | Blue Cross Blue Shield of Illinois |
| M9T | Blue Cross Blue Shield of Texas |
| M9X | Unassigned Prefix |
| MAA | Premera Blue Cross |
| MAB | BCBS of Florida |
| MAC | BCBS of Minnesota |
| MAD | Premera Blue Cross |
| MAE | Anthem BCBS of Ohio |
| MAF | Carefirst BCBS of Maryland |
| MAG | BCBS of New Mexico |
| MAH | Anthem BCBS of Virginia |
| MAI | Wellmark BCBS |
| MAJ | Blue Shield of California |
| MAK | Anthem BCBS of Kentucky |
| MAL | Carefirst BCBS of Maryland |
| MAM | Carefirst BCBS |
| MAN | Carefirst BCBS of Maryland |
| MAO | BCBS of South Carolina |
| MAP | Anthem BCBS of Colorado |
| MAQ | BCBS of Florida |
| MAR | Anthem BCBS of Georgia |
| MAS | Anthem BCBS of Georgia |
| MAT | BCBS of Texas |
| MAU | Wellmark BCBS |
| MAV | Anthem BCBS of Ohio |
| MAW | Carefirst BCBS of Maryland |
| MAX | BCBS of Illinois |
| MAY | BCBS of Nebraska |
| MAZ | Wellmark BCBS |
| MBA | Anthem BCBS of Ohio |
| MBB | Anthem BCBS of Colorado |
| MBC | BCBS of Tennessee |
| MBD | Carefirst BCBS of Maryland |
| MBE | BCBS of South Carolina |
| MBF | Anthem Blue Cross of California |
| MBG | BCBS of Alabama |
| MBH | BCBS of Alabama |
| MBI | BCBS of Michigan |
| MBJ | Regence Blue Shield of Washington |
| MBK | Empire BCBS of New York |
| MBL | Anthem Blue Cross of California |
| MBM | BCBS of Illinois |
| MBN | BCBS of Michigan |
| MBO | BCBS of Florida |
| MBP | Anthem BCBS of Indiana |
| MBQ | Wellmark BCBS |
| MBR | Anthem Blue Cross of California |
| MBS | Carefirst BCBS |
| MBT | Anthem BCBS of Missouri |
| MBU | BCBS of Massachusetts |
| MBV | Carefirst BCBS of Maryland |
| MBW | Anthem BCBS of Ohio |
| MBX | Unassigned Prefix |
| MBY | Unassigned Prefix |
| MBZ | Carefirst BCBS of Maryland |
| MCA | Blue Shield of California |
| MCB | Unassigned Prefix |
| MCC | BCBS of Texas |
| MCD | BCBS of Illinois |
| MCE | Premera Blue Cross |
| MCF | Carefirst BCBS of Maryland |
| MCG | Carefirst BCBS of Maryland |
| MCH | BCBS of Florida |
| MCI | Anthem Blue Cross of California |
| MCJ | Highmark BCBS |
| MCK | Wellmark BCBS |
| MCL | Wellmark BCBS |
| MCM | Premera Blue Cross |
| MCN | BCBS of Kansas City |
| MCO | Anthem BCBS of Virginia |
| MCP | Unassigned Prefix |
| MCQ | BCBS of Illinois |
| MCR | Carefirst BCBS of Maryland |
| MCS | Carefirst BCBS of Maryland |
| MCT | Wellmark BCBS |
| MCU | Anthem Blue Cross of California |
| MCV | Wellmark BCBS |
| MCW | Wellmark BCBS |
| MCX | BCBS of Massachusetts |
| MCY | Highmark BCBS |
| MCZ | Anthem BCBS of Ohio |
| MDA | BCBS of Michigan |
| MDB | BCBS of Alabama |
| MDC | BCBS of Minnesota |
| MDD | BCBS of Georgia |
| MDE | Anthem Blue Cross of California |
| MDF | Independence Blue Cross |
| MDG | BCBS of Michigan |
| MDH | BCBS of Rhose Island |
| MDI | Wellmark BCBS |
| MDJ | Anthem BCBS of Indiana |
| MDK | BCBS of Arizona |
| MDL | BCBS of Illinois |
| MDM | Carefirst BCBS of Maryland |
| MDN | Anthem BCBS of Wisconsin |
| MDO | Wellmark BCBS |
| MDP | Blue Shield of California |
| MDQ | BCBS of Minnesota |
| MDR | Anthem BCBS of Wisconsin |
| MDS | Carefirst BCBS of Maryland |
| MDT | Carefirst Administrators |
| MDU | Wellmark BCBS |
| MDV | BCBS of Illinois |
| MDW | Wellmark BCBS |
| MDX | BCBS of Alabama |
| MDY | BCBS of Kansas City |
| MDZ | BCBS of Minnesota |
| MEA | Blue Shield of California |
| MEB | Unassigned Prefix |
| MEC | Anthem BCBS of Virginia |
| MED | Anthem BCBS of Ohio |
| MEE | BCBS of Massachusetts |
| MEF | Carefirst BCBS of Maryland |
| MEG | Anthem BCBS of Georgia |
| MEH | Carefirst BCBS of Maryland |
| MEI | BCBS of Michigan |
| MEJ | Carefirst BCBS of Maryland |
| MEK | Blue Shield of California |
| MEL | Wellmark BCBS |
| MEM | Wellmark BCBS |
| MEN | Anthem BCBS of Maine |
| MEO | Blue Shield of California |
| MEP | Anthem BCBS of Maine |
| MEQ | Blue Shield of California |
| MER | Anthem BCBS of Wisconsin |
| MES | BCBS of Illinois |
| MET | BCBS of Nebraska |
| MEU | BCBS of Texas |
| MEV | Unassigned Prefix |
| MEW | Anthem BCBS of Maine |
| MEX | BCBS of New Mexico |
| MEY | Anthem BCBS of Maine |
| MEZ | BCBS of New Mexico |
| MFA | BCBS of Illinois |
| MFB | Wellmark BCBS |
| MFC | Carefirst BCBS of Maryland |
| MFD | Anthem BCBS of Georgia |
| MFE | Anthem Blue Cross of California |
| MFF | Regence BCBS of Oregon |
| MFG | Anthem BCBS of Ohio |
| MFH | Anthem BCBS of Georgia |
| MFI | Wellmark BCBS |
| MFJ | BCBS of Wisconsin |
| MFK | BCBS of Mississippi |
| MFL | Independence Blue Cross |
| MFM | Anthem BCBS of Georgia |
| MFN | Anthem BCBS of Virginia |
| MFO | Anthem BCBS of Wisconsin |
| MFP | Regence BCBS of Oregon |
| MFQ | Anthem BCBS of Virginia |
| MFR | Unassigned Prefix |
| MFS | Carefirst Administrators |
| MFT | Anthem Blue Cross of California |
| MFU | Wellmark BCBS |
| MFV | BCBS of Illinois |
| MFW | Anthem Blue Cross of California |
| MFX | BCBS of Michigan |
| MFY | BCBS of Minnesota |
| MGA | Independence Blue Cross |
| MGB | Capital Blue Cross |
| MGC | Unassigned Prefix |
| MGD | Premera Blue Cross |
| MGE | BCBS of Rhode Island |
| MGF | Anthem BCBS of Nevada |
| MGG | Independence Blue Cross |
| MGH | BCBS of Massachusetts |
| MGI | Highmark BCBS |
| MGJ | Anthem BCBS of Missouri |
| MGK | Wellmark BCBS |
| MGL | Independence Blue Cross |
| MGM | Carefirst BCBS of Maryland |
| MGN | Unassigned Prefix |
| MGO | BCBS of Michigan |
| MGP | Wellmark BCBS |
| MGQ | BCBS of Minnesota |
| MGR | BCBS of Michigan |
| MGS | BCBS of Georgia |
| MGT | Regence BCBS of Oregon |
| MGU | Anthem BCBS of Virginia |
| MGV | BCBS of South Carolina |
| MGW | BCBS of Arkansas |
| MGX | BCBS of Massachusetts |
| MGY | Blue Shield of California |
| MGZ | Horizon BCBS of New Jersey |
| MHA | BCBS of South Carolina |
| MHB | BCBS of Texas |
| MHC | Highmark BCBS |
| MHD | Empire BCBS of New York |
| MHE | Unassigned Prefix |
| MHF | Wellmark BCBS |
| MHG | Anthem Blue Cross of California |
| MHH | BCBS of Michigan |
| MHI | Anthem BCBS of Georgia |
| MHJ | Unassigned Prefix |
| MHK | Wellmark BCBS |
| MHL | BCBS of South Carolina |
| MHM | Carefirst BCBS of Maryland |
| MHN | Anthem BCBS of Ohio |
| MHO | Unassigned Prefix |
| MHP | Empire BCBS |
| MHQ | Anthem BCBS of Georgia |
| MHR | Unassigned Prefix |
| MHS | BCBS of Nebraska |
| MHT | Carefirst BCBS of Maryland |
| MHU | Unassigned Prefix |
| MHV | Unassigned Prefix |
| MHW | BCBS of Alabama |
| MHX | BCBS of Georgia |
| MHY | Anthem Blue Cross of California |
| MHZ | Wellmark BCBS |
| MIA | Blue Shield of California |
| MIB | BCBS of Minnesota |
| MIC | BCBS of South Carolina |
| MID | Unassigned Prefix |
| MIE | BCBS of Minnesota |
| MIF | Anthem BCBS of Ohio |
| MIG | BCBS of Michigan |
| MIH | BCBS of Georgia |
| MII | BCBS of Kansas City |
| MIJ | BCBS of Michigan |
| MIK | Unassigned Prefix |
| MIL | BCBS of Massachusetts |
| MIM | Highmark BCBS |
| MIN | Premera Blue Cross |
| MIO | Blue Shield of California |
| MIP | Blue Cross of Idaho |
| MIQ | Anthem BCBS of Ohio |
| MIR | Unassigned Prefix |
| MIS | Anthem BCBS of Ohio |
| MIT | Wellmark BCBS |
| MIU | BCBS of South Carolina |
| MIV | BCBS of Western New York |
| MIW | BCBS of Michigan |
| MIX | Blue Shield of California |
| MIY | Unassigned Prefix |
| MIZ | Blue Shield of California |
| MJA | Blue Shield of Northeastern New York |
| MJB | Anthem BCBS of Colorado |
| MJC | BCBS of Texas |
| MJD | BCBS of Alabama |
| MJE | BCBS of Michigan |
| MJF | Carefirst BCBS |
| MJG | Premera Blue Cross |
| MJH | Anthem BCBS of Wisconsin |
| MJI | Carefirst BCBS of Maryland |
| MJJ | BCBS of Michigan |
| MJK | Carefirst BCBS |
| MJL | Anthem Blue Cross of California |
| MJM | Highmark BCBS |
| MJN | Highmark BCBS |
| MJO | Anthem BCBS of Connecticut |
| MJP | Wellmark BCBS |
| MJQ | Anthem Blue Cross of California |
| MJR | BCBS of Michigan |
| MJS | BCBS of Texas |
| MJT | BCBS of Michigan |
| MJU | BCBS of Michigan |
| MJV | Anthem BCBS of Missouri |
| MJW | BCBS of Georgia |
| MJX | BCBS of Michigan |
| MJY | Unassigned Prefix |
| MJZ | Unassigned Prefix |
| MKA | Wellmark BCBS |
| MKB | Blue Shield of California |
| MKC | BCBS of South Carolina |
| MKD | BCBS of Massachusetts |
| MKE | BCBS of Tennessee |
| MKF | Premera Blue Cross |
| MKG | Anthem BCBS of Ohio |
| MKH | BCBS of Tennessee |
| MKI | BCBS of Tennessee |
| MKJ | Anthem BCBS of Ohio |
| MKK | Anthem Blue Cross of California |
| MKL | BCBS of Mississippi |
| MKM | Carefirst BCBS of Maryland |
| MKN | Anthem BCBS of Virginia |
| MKO | BCBS of Michigan |
| MKP | Anthem BCBS of Virginia |
| MKQ | Anthem Blue Cross of California |
| MKR | BCBS of Illinois |
| MKS | BCBS of Massachusetts |
| MKT | Wellmark BCBS |
| MKU | Premera Blue Cross |
| MKV | Horizon BCBS of New Jersey |
| MKW | BCBS of Florida |
| MKX | Anthem BCBS of Virginia |
| MKY | Horizon BCBS of New Jersey |
| MKZ | Carefirst BCBS of Maryland |
| MLA | Wellmark BCBS |
| MLB | Unassigned Prefix |
| MLC | BCBS of Illinois |
| MLD | Unassigned Prefix |
| MLE | BCBS of Illinois |
| MLF | Carefirst BCBS |
| MLG | Highmark BCBS |
| MLH | Carefirst BCBS of Maryland |
| MLI | Independence Blue Cross |
| MLJ | Carefirst BCBS of Maryland |
| MLK | Anthem BCBS of Virginia |
| MLL | Blue Shield of California |
| MLM | Highmark BCBS |
| MLN | Blue Shield of California |
| MLO | BCBS of Western New York |
| MLP | Anthem BCBS of Virginia |
| MLQ | BCBS of Minnesota |
| MLR | BCBS of Massachusetts |
| MLS | BCBS of Alabama |
| MLT | BCBS of Nebraska |
| MLU | BCBS of Minnesota |
| MLV | BCBS of Minnesota |
| MLW | BCBS of Georgia |
| MLX | Carefirst BCBS of Maryland |
| MLY | Premera Blue Cross |
| MLZ | BCBS of Rhode Island |
| MMA | Empire BCBS |
| MMB | Carefirst BCBS of Maryland |
| MMC | Unassigned Prefix |
| MMD | Premera Blue Cross |
| MME | Carefirst BCBS |
| MMF | Excellus BCBS of New York |
| MMG | BCBS of Mississippi |
| MMH | Empire BCBS |
| MMI | Independence Blue Cross |
| MMJ | BCBS of Michigan |
| MMK | BCBS of Illinois |
| MML | BCBS of Illinois |
| MMM | BCBS of Minnesota |
| MMN | BCBS of Tennessee |
| MMO | BCBS of Michigan |
| MMP | BCBS of North Carolina |
| MMQ | Anthem BCBS of Ohio |
| MMR | BCBS of Massachusetts |
| MMS | Anthem BCBS of Ohio |
| MMT | Carefirst Administrators |
| MMU | BCBS of Illinois |
| MMV | Anthem BCBS of Ohio |
| MMW | BCBS of Illinois |
| MMX | BCBS of Alabama |
| MMY | Unassigned Prefix |
| MMZ | Wellmark BCBS |
| MNA | BCBS of Minnesota |
| MNB | BCBS of Massachusetts |
| MNC | Anthem Blue Cross of California |
| MND | Anthem BCBS of Wisconsin |
| MNE | Anthem BCBS of Wisconsin |
| MNF | Independence Blue Cross |
| MNG | BCBS of Tennessee |
| MNH | Anthem BCBS of Virginia |
| MNI | BCBS of Georgia |
| MNJ | Anthem BCBS of Ohio |
| MNK | BCBS of Michigan |
| MNL | BCBS of South Carolina |
| MNM | BCBS of Minnesota |
| MNN | Highmark BCBS |
| MNO | BCBS of North Carolina |
| MNP | Blue Shield of California |
| MNQ | BCBS of Minnesota |
| MNR | BCBS of Minnesota |
| MNS | Anthem BCBS of Kentucky |
| MNT | BCBS of Illinois |
| MNU | BCBS of North Carolina |
| MNV | Unassigned Prefix |
| MNW | Premera Blue Cross |
| MNX | BCBS of Illinois |
| MNY | Premera Blue Cross |
| MNZ | Wellmark BCBS |
| MOA | BCBS of Massachusetts |
| MOB | Unassigned Prefix |
| MOC | BCBS of Georgia |
| MOD | BCBS of Massachusetts |
| MOE | BCBS of Illinois |
| MOF | Blue Shield of California |
| MOG | BCBS of South Carolina |
| MOH | Unassigned Prefix |
| MOI | BCBS of Massachusetts |
| MOJ | Anthem BCBS of Ohio |
| MOK | Independence Blue Cross |
| MOL | Unassigned Prefix |
| MOM | Anthem Blue Cross of California |
| MON | Unassigned Prefix |
| MOO | Unassigned Prefix |
| MOP | Unassigned Prefix |
| MOQ | Independence Blue Cross |
| MOR | Premera Blue Cross |
| MOS | Blue Shield of California |
| MOT | BCBS of Massachusetts |
| MOU | BCBS of Michigan |
| MOV | BCBS of Arkansas |
| MOW | Anthem BCBS of Kentucky |
| MOX | BCBS of Illinois |
| MOY | Wellmark BCBS |
| MOZ | Unassigned Prefix |
| MPA | BCBS of Mississippi |
| MPB | Unassigned Prefix |
| MPC | BCBS of Rhose Island |
| MPD | BCBS of Texas |
| MPE | BCBS of Michigan |
| MPF | Excellus BCBS of New York |
| MPG | Independence Blue Cross |
| MPH | BCBS of Massachusetts |
| MPI | Anthem Blue Cross of California |
| MPJ | Unassigned Prefix |
| MPK | Unassigned Prefix |
| MPL | BCBS of Illinois |
| MPM | Highmark BCBS |
| MPN | Wellmark BCBS |
| MPO | BCBS of Alabama |
| MPP | Anthem BCBS of Wisconsin |
| MPQ | BCBS of Minnesota |
| MPR | Anthem Blue Cross of California |
| MPS | BCBS of Georgia |
| MPT | BCBS of Minnesota |
| MPU | Anthem BCBS of Ohio |
| MPV | BCBS of Minnesota |
| MPW | BCBS of Nebraska |
| MPX | BCBS of Minnesota |
| MPY | BCBS of Florida |
| MPZ | Unassigned Prefix |
| MQA | BCBS of Michigan |
| MQB | Empire BCBS |
| MQC | Anthem Blue Cross of California |
| MQD | Carefirst Administrators |
| MQE | Anthem BCBS of Georgia |
| MQF | BCBS of Western New York |
| MQG | Carefirst BCBS |
| MQH | BCBS of Michigan |
| MQI | Wellmark BCBS |
| MQJ | BCBS of Michigan |
| MQK | BCBS of Michigan |
| MQL | Anthem BCBS of Georgia |
| MQM | Unassigned Prefix |
| MQN | BCBS of North Carolina |
| MQO | BCBS of Michigan |
| MQP | Anthem Blue Cross of California |
| MQQ | Blue Cross of Idaho |
| MQR | Highmark BCBS |
| MQS | Unassigned Prefix |
| MQT | BCBS of Minnesota |
| MQU | Anthem BCBS of Ohio |
| MQV | BCBS of Nebraska |
| MQW | BCBS of Michigan |
| MQX | Anthem Blue Cross of California |
| MQY | BCBS of North Carolina |
| MQZ | Anthem Blue Cross of California |
| MRA | Anthem BCBS of Virginia |
| MRB | Unassigned Prefix |
| MRC | BCBS of Illinois |
| MRD | Unassigned Prefix |
| MRE | Wellmark BCBS |
| MRF | BCBS of Michigan |
| MRG | BCBS of Illinois |
| MRH | Anthem BCBS of Wisconsin |
| MRI | Blue Shield of California |
| MRJ | Carefirst BCBS of Maryland |
| MRK | BCBS of Massachusetts |
| MRL | Wellmark BCBS |
| MRM | BCBS of Kansas City |
| MRN | Anthem BCBS of Wisconsin |
| MRO | Unassigned Prefix |
| MRP | Anthem BCBS of Wisconsin |
| MRQ | BCBS of Western New York |
| MRR | Anthem Blue Cross of California |
| MRS | Wellmark BCBS |
| MRT | BCBS of Texas |
| MRU | Highmark BCBS |
| MRV | Anthem Blue Cross of California |
| MRW | BCBS of Illinois |
| MRX | Anthem BCBS of Wisconsin |
| MRY | BCBS of Alabama |
| MRZ | BCBS of Illinois |
| MSA | BCBS of Alabama |
| MSB | Wellmark BCBS |
| MSC | BCBS of Alabama |
| MSD | Independence Blue Cross |
| MSE | BCBS of Michigan |
| MSF | Empire BCBS of New York |
| MSG | BCBS of Michigan |
| MSH | BCBS of Michigan |
| MSI | Regence BCBS of Oregon |
| MSJ | Premera Blue Cross |
| MSK | BCBS of Massachusetts |
| MSL | Carefirst Administrators |
| MSM | Carefirst BCBS of Maryland |
| MSN | Anthem BCBS of Ohio |
| MSO | BCBS of Nebraska |
| MSP | Premera Blue Cross |
| MSQ | Premera Blue Cross |
| MSR | BCBS of Michigan |
| MSS | Highmark BCBS |
| MST | Premera Blue Cross |
| MSU | Anthem BCBS of Ohio |
| MSV | BCBS of Alabama |
| MSW | BCBS of Illinois |
| MSX | Anthem Blue Cross of California |
| MSY | Premera Blue Cross |
| MSZ | Anthem Blue Cross of California |
| MTA | Anthem BCBS of Virginia |
| MTB | Wellmark BCBS |
| MTC | Anthem BCBS of Virginia |
| MTD | Premera Blue Cross |
| MTE | Blue Shield of California |
| MTF | Anthem BCBS of Georgia |
| MTG | Carefirst BCBS of Maryland |
| MTH | Wellmark BCBS |
| MTI | Empire BCBS of New York |
| MTJ | Blue Cross of Idaho |
| MTK | Wellmark BCBS |
| MTL | BCBS of Texas |
| MTM | BCBS of South Carolina |
| MTN | BCBS of Massachusetts |
| MTO | Blue Shield of California |
| MTP | BCBS of Massachusetts |
| MTQ | Blue Shield of California |
| MTR | BCBS of Tennessee |
| MTS | Carefirst BCBS of Maryland |
| MTT | Blue Shield of California |
| MTU | Premera Blue Cross |
| MTV | Anthem BCBS of Indiana |
| MTW | Anthem BCBS of Ohio |
| MTX | Carefirst Administrators |
| MTY | Anthem Blue Cross of California |
| MTZ | BCBS of Illinois |
| MUA | BCBS of Texas |
| MUB | Carefirst BCBS of Maryland |
| MUC | Wellmark BCBS |
| MUD | Carefirst BCBS of Maryland |
| MUE | Wellmark BCBS |
| MUF | Anthem BCBS of Wisconsin |
| MUG | BCBS of Arkansas |
| MUH | Carefirst BCBS of Maryland |
| MUI | Unassigned Prefix |
| MUJ | BCBS of Georgia |
| MUK | Anthem BCBS of Wisconsin |
| MUL | BCBS of Illinois |
| MUM | BCBS of Arizona |
| MUN | BCBS of Illinois |
| MUO | Anthem BCBS of Wisconsin |
| MUP | BCBS of Minnesota |
| MUQ | Premera Blue Cross |
| MUR | BCBS of Michigan |
| MUS | BCBS of Texas |
| MUT | BCBS of Minnesota |
| MUU | BCBS of Michigan |
| MUV | Carefirst BCBS |
| MUW | Highmark BCBS |
| MUX | Wellmark BCBS |
| MUY | BCBS of Alabama |
| MUZ | BCBS of Michigan |
| MVA | BCBS of Montana |
| MVB | BCBS of Vermont |
| MVC | BCBS of South Carolina |
| MVD | Premera Blue Cross |
| MVE | BCBS of Massachusetts |
| MVF | Empire BCBS of New York |
| MVG | BCBS of Minnesota |
| MVH | Unassigned Prefix |
| MVI | BCBS of Michigan |
| MVJ | Blue Shield of California |
| MVK | BCBS of Georgia |
| MVL | BCBS of Massachusetts |
| MVM | BCBS of Alabama |
| MVN | Empire BCBS of New York |
| MVO | Blue Shield of California |
| MVP | Carefirst BCBS |
| MVQ | Blue Cross of Idaho |
| MVR | Highmark BCBS |
| MVS | Blue Shield of California |
| MVT | BCBS of Minnesota |
| MVU | Anthem BCBS of Ohio |
| MVV | Wellmark BCBS |
| MVW | Unassigned Prefix |
| MVX | BCBS of South Carolina |
| MVY | Anthem BCBS of Ohio |
| MVZ | Highmark BCBS |
| MWA | BCBS of Illinois |
| MWB | Unassigned Prefix |
| MWC | Unassigned Prefix |
| MWD | Carefirst Administrators |
| MWE | Anthem BCBS of Wisconsin |
| MWF | BCBS of Illinois |
| MWG | BCBS of Minnesota |
| MWH | BCBS of Illinois |
| MWI | Unassigned Prefix |
| MWJ | Horizon BCBS of New Jersey |
| MWK | Horizon BCBS of New Jersey |
| MWL | BCBS of Illinois |
| MWM | BCBS of Georgia |
| MWN | BCBS of Illinois |
| MWO | Independence Blue Cross |
| MWP | BCBS of Massachusetts |
| MWQ | Anthem BCBS of Virginia |
| MWR | BCBS of Kansas City |
| MWS | Anthem BCBS of Virginia |
| MWT | Blue Shield of California |
| MWU | Anthem BCBS of Wisconsin |
| MWV | Anthem BCBS of Wisconsin |
| MWW | Anthem BCBS of Nevada |
| MWX | BCBS of Alabama |
| MWY | Unassigned Prefix |
| MWZ | Independence Blue Cross |
| MXA | Anthem Blue Cross of California |
| MXB | Highmark BCBS |
| MXC | Unassigned Prefix |
| MXD | BCBS of Texas |
| MXE | BCBS of Texas |
| MXF | Empire BCBS of New York |
| MXG | BCBS of Massachusetts |
| MXH | Carefirst BCBS of Maryland |
| MXI | Blue Shield of California |
| MXJ | Anthem BCBS of Virginia |
| MXK | Capital Blue Cross |
| MXL | Wellmark BCBS |
| MXM | Wellmark BCBS |
| MXN | BCBS of Massachusetts |
| MXO | Wellmark BCBS |
| MXP | BCBS of Massachusetts |
| MXQ | Empire BCBS |
| MXR | Anthem Blue Cross of California |
| MXS | Anthem BCBS of Georgia |
| MXT | Unassigned Prefix |
| MXU | Anthem BCBS of Connecticut |
| MXV | Blue Cross of Idaho |
| MXW | Blue Cross of Idaho |
| MXX | BCBS of Minnesota |
| MXY | BCBS of Massachusetts |
| MXZ | Premera Blue Cross |
| MYA | Unassigned Prefix |
| MYB | Regence BCBS of Oregon |
| MYC | Unassigned Prefix |
| MYD | BCBS of Massachusetts |
| MYE | Anthem BCBS of Ohio |
| MYF | Empire BCBS of New York |
| MYG | Wellmark BCBS |
| MYH | BCBS of Massachusetts |
| MYI | BCBS of Massachusetts |
| MYJ | Unassigned Prefix |
| MYK | BCBS of Massachusetts |
| MYL | BCBS of Massachusetts |
| MYM | Anthem BCBS of Ohio |
| MYN | Anthem BCBS of Ohio |
| MYO | Unassigned Prefix |
| MYP | BCBS of Georgia |
| MYQ | BCBS of Massachusetts |
| MYR | BCBS of Alabama |
| MYS | BCBS of Massachusetts |
| MYT | BCBS of Michigan |
| MYU | BCBS of Massachusetts |
| MYV | Regence Blue Cross Blue Shield of Utah |
| MYW | Carefirst BCBS of Maryland |
| MYX | BCBS of Oklahoma |
| MYY | Carefirst BCBS of Maryland |
| MYZ | BCBS of Massachusetts |
| MZA | Wellmark BCBS |
| MZB | Highmark BCBS |
| MZC | BCBS of Rhose Island |
| MZD | BCBS of Illinois |
| MZE | BCBS of Massachusetts |
| MZF | BCBS of Illinois |
| MZG | BCBS of Illinois |
| MZH | Unassigned Prefix |
| MZI | Blue Shield of California |
| MZJ | BCBS of Massachusetts |
| MZK | Anthem BCBS of Virginia |
| MZL | BCBS of Alabama |
| MZM | BCBS of Minnesota |
| MZN | BCBS of North Carolina |
| MZO | BCBS of Michigan |
| MZP | BCBS of Michigan |
| MZQ | BCBS of Minnesota |
| MZR | BCBS of Minnesota |
| MZS | BCBS of North Carolina |
| MZT | BCBS of Minnesota |
| MZU | BCBS of South Carolina |
| MZV | BCBS of Michigan |
| MZW | BCBS of Minnesota |
| MZX | BCBS of Minnesota |
| MZY | BCBS of Michigan |
| MZZ | BCBS of Minnesota |