| Alpha Prefix | BCBS Home Plan Name | BCBS Home Plan Website |
| MAA | Wellmark BCBS | https://www.wellmark.com/ |
| MAB | BCBS of Florida | https://www.floridablue.com/ |
| MAC | Prefix Not in Use | https://www.bcbs.com/member-services |
| MAE | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MAF | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MAG | Unknown Assignment | https://www.bcbs.com/ |
| MAH | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MAI | Wellmark BCBS | https://www.wellmark.com/ |
| MAL | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MAM | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MAN | Prefix Not in Use | https://www.bcbs.com/member-services |
| MAO | BCBS of Florida | https://www.floridablue.com/ |
| MAQ | BCBS of Florida | https://www.floridablue.com/ |
| MAT | BCBS of Texas | https://www.bcbstx.com/ |
| MAU | Wellmark BCBS | https://www.wellmark.com/ |
| MAV | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MAW | Anthem BCBS of Connecticut | https://www.anthem.com/individual-and-family/health-insurance/connecticut/ |
| MAY | BCBS of Nebraska | https://www.nebraskablue.com/ |
| MAZ | Wellmark BCBS | https://www.wellmark.com/ |
| MBA | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MBC | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MBD | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MBE | BCBS of Nebraska | https://www.nebraskablue.com/ |
| MBF | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MBG | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MBH | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MBJ | Regence | https://www.regence.com/member/home |
| MBK | Empire BCBS of New York | https://www.empireblue.com/ |
| MBN | BCBS of Michigan | https://www.bcbsm.com/ |
| MBO | BCBS of Florida | https://www.floridablue.com/ |
| MBP | Anthem BCBS of Indiana | https://www.anthem.com/individual-and-family/health-insurance/indiana/ |
| MBQ | Wellmark BCBS | https://www.wellmark.com/ |
| MBR | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MBS | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MBT | Anthem BCBS of Missouri | https://www.anthem.com/individual-and-family/health-insurance/missouri/ |
| MBU | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MBV | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MBW | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MBX | Prefix Not in Use | https://www.bcbs.com/member-services |
| MBY | Prefix Not in Use | https://www.bcbs.com/member-services |
| MBZ | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MCA | Blue Shield of California | https://blueshieldcaplans.com/ |
| MCC | BCBS of Texas | https://www.bcbstx.com/ |
| MCD | BCBS of Illinois | https://www.bcbsil.com/ |
| MCF | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MCG | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MCH | BCBS of Florida | https://www.floridablue.com/ |
| MCI | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MCJ | Highmark BCBS | https://www.highmarkbcbswv.com/home/ |
| MCK | Wellmark BCBS | https://www.wellmark.com/ |
| MCL | Wellmark BCBS | https://www.wellmark.com/ |
| MCM | Prefix Not in Use | https://www.bcbs.com/member-services |
| MCP | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MCQ | BCBS of Illinois | https://www.bcbsil.com/ |
| MCR | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MCS | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MCT | Wellmark BCBS | https://www.wellmark.com/ |
| MCU | Prefix Not in Use | https://www.bcbs.com/member-services |
| MCV | Wellmark BCBS | https://www.wellmark.com/ |
| MCW | Wellmark BCBS | https://www.wellmark.com/ |
| MCX | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MCY | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MCZ | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MDA | BCBS of Michigan | https://www.bcbsm.com/ |
| MDB | Prefix Not in Use | https://www.bcbs.com/member-services |
| MDC | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MDD | Prefix Not in Use | https://www.bcbs.com/member-services |
| MDE | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MDG | BCBS of Michigan | https://www.bcbsm.com/ |
| MDI | Wellmark BCBS | https://www.wellmark.com/ |
| MDK | BCBS of Arizona | https://www.azblue.com/individualsandfamilies |
| MDL | BCBS of Illinois | https://www.bcbsil.com/ |
| MDM | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MDN | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MDO | Wellmark BCBS | https://www.wellmark.com/ |
| MDQ | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MDR | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MDS | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MDT | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MDU | Wellmark BCBS | https://www.wellmark.com/ |
| MDV | Prefix Not in Use | https://www.bcbs.com/member-services |
| MDW | Wellmark BCBS | https://www.wellmark.com/ |
| MDX | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MDY | Unknown Assignment | https://www.bcbs.com/ |
| MDZ | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MEA | Blue Shield of California | https://blueshieldcaplans.com/ |
| MEC | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MED | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MEE | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MEF | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MEH | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MEI | BCBS of Michigan | https://www.bcbsm.com/ |
| MEJ | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MEK | Blue Shield of California | https://blueshieldcaplans.com/ |
| MEL | Wellmark BCBS | https://www.wellmark.com/ |
| MEN | Anthem BCBS of Maine | https://www.anthem.com/individual-and-family/health-insurance/maine/ |
| MEO | Blue Shield of California | https://blueshieldcaplans.com/ |
| MEP | Anthem BCBS of Maine | https://www.anthem.com/individual-and-family/health-insurance/maine/ |
| MEQ | Blue Shield of California | https://blueshieldcaplans.com/ |
| MER | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MES | BCBS of Oklahoma | https://www.bcbsok.com/ |
| MET | BCBS of Nebraska | https://www.nebraskablue.com/ |
| MEV | Prefix Not in Use | https://www.bcbs.com/member-services |
| MEX | Unknown Assignment | https://www.bcbs.com/ |
| MEZ | Unknown Assignment | https://www.bcbs.com/ |
| MFA | BCBS of Illinois | https://www.bcbsil.com/ |
| MFB | Wellmark BCBS | https://www.wellmark.com/ |
| MFC | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MFE | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MFG | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MFI | Wellmark BCBS | https://www.wellmark.com/ |
| MFK | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MFL | Independence Blue Cross | https://www.ibx.com/index.jsp |
| MFN | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MFQ | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MFR | Prefix Not in Use | https://www.bcbs.com/member-services |
| MFS | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MFT | Prefix Not in Use | https://www.bcbs.com/member-services |
| MFU | Wellmark BCBS | https://www.wellmark.com/ |
| MFV | BCBS of Illinois | https://www.bcbsil.com/ |
| MFW | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MFY | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MFZ | BCBS of Illinois | https://www.bcbsil.com/ |
| MGA | Blue Shield of California | https://blueshieldcaplans.com/ |
| MGB | Capital Blue Cross | https://www.capbluecross.com/ |
| MGD | Premera Blue Cross | https://www.premera.com/visitor |
| MGE | BCBS of Rhode Island | https://www.bcbsri.com/ |
| MGF | Prefix Not in Use | https://www.bcbs.com/member-services |
| MGG | Blue Shield of California | https://blueshieldcaplans.com/ |
| MGH | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MGK | Wellmark BCBS | https://www.wellmark.com/ |
| MGL | Independence Blue Cross | https://www.ibx.com/index.jsp |
| MGM | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MGO | BCBS of Michigan | https://www.bcbsm.com/ |
| MGP | Wellmark BCBS | https://www.wellmark.com/ |
| MGQ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MGR | BCBS of Michigan | https://www.bcbsm.com/ |
| MGS | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MGU | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MGV | BCBS of South Carolina | https://www.southcarolinablues.com/web/public/brands/sc/ |
| MGX | Prefix Not in Use | https://www.bcbs.com/member-services |
| MGY | Blue Shield of California | https://blueshieldcaplans.com/ |
| MGZ | Horizon BCBS of New Jersey | https://www.horizonblue.com/ |
| MHA | Unknown Assignment | https://www.bcbs.com/ |
| MHB | BCBS of Texas | https://www.bcbstx.com/ |
| MHC | Highmark BCBS | https://www.highmarkblueshield.com/home/ |
| MHD | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHF | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHH | BCBS of Michigan | https://www.bcbsm.com/ |
| MHJ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHK | Wellmark BCBS | https://www.wellmark.com/ |
| MHL | Unknown Assignment | https://www.bcbs.com/ |
| MHM | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MHN | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MHS | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHT | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MHU | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHV | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHW | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MHX | Prefix Not in Use | https://www.bcbs.com/member-services |
| MHY | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MHZ | Wellmark BCBS | https://www.wellmark.com/ |
| MIB | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MIC | BCBS of South Carolina | https://www.southcarolinablues.com/web/public/brands/sc/ |
| MID | Prefix Not in Use | https://www.bcbs.com/member-services |
| MIE | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MIF | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MIG | BCBS of Michigan | https://www.bcbsm.com/ |
| MIH | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MII | Unknown Assignment | https://www.bcbs.com/ |
| MIJ | BCBS of Michigan | https://www.bcbsm.com/ |
| MIK | Capital Blue Cross | https://www.capbluecross.com/ |
| MIM | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MIO | Blue Shield of California | https://blueshieldcaplans.com/ |
| MIP | Blue Cross of Idaho | https://www.bcidaho.com/ |
| MIQ | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MIR | Prefix Not in Use | https://www.bcbs.com/member-services |
| MIS | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MIT | Wellmark BCBS | https://www.wellmark.com/ |
| MIU | BCBS of South Carolina | https://www.southcarolinablues.com/web/public/brands/sc/ |
| MIV | BCBS of Western New York | https://www.bcbswny.com/ |
| MIW | BCBS of Michigan | https://www.bcbsm.com/ |
| MIX | Blue Shield of California | https://blueshieldcaplans.com/ |
| MIY | Prefix Not in Use | https://www.bcbs.com/member-services |
| MIZ | Blue Shield of California | https://blueshieldcaplans.com/ |
| MJA | BCBS of Western New York | https://www.bcbswny.com/ |
| MJD | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MJE | BCBS of Michigan | https://www.bcbsm.com/ |
| MJF | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MJG | Premera Blue Cross | https://www.premera.com/visitor |
| MJI | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MJJ | BCBS of Michigan | https://www.bcbsm.com/ |
| MJL | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MJM | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MJN | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MJP | Wellmark BCBS | https://www.wellmark.com/ |
| MJR | BCBS of Michigan | https://www.bcbsm.com/ |
| MJS | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MJT | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MJU | BCBS of Michigan | https://www.bcbsm.com/ |
| MJW | Prefix Not in Use | https://www.bcbs.com/member-services |
| MJX | BCBS of Michigan | https://www.bcbsm.com/ |
| MJY | BCBS of Illinois | https://www.bcbsil.com/ |
| MJZ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MKA | Wellmark BCBS | https://www.wellmark.com/ |
| MKB | Blue Shield of California | https://blueshieldcaplans.com/ |
| MKC | BCBS of South Carolina | https://www.southcarolinablues.com/web/public/brands/sc/ |
| MKD | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MKE | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MKF | Prefix Not in Use | https://www.bcbs.com/member-services |
| MKG | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MKH | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MKI | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MKJ | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MKK | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MKL | BCBS of Mississippi | https://www.bcbsms.com/ |
| MKM | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MKN | Prefix Not in Use | https://www.bcbs.com/member-services |
| MKO | BCBS of Michigan | https://www.bcbsm.com/ |
| MKP | Prefix Not in Use | https://www.bcbs.com/member-services |
| MKQ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MKS | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MKT | Wellmark BCBS | https://www.wellmark.com/ |
| MKU | Premera Blue Cross | https://www.premera.com/visitor |
| MKV | Horizon BCBS of New Jersey | https://www.horizonblue.com/ |
| MKW | Wellmark BCBS | https://www.wellmark.com/ |
| MKX | Prefix Not in Use | https://www.bcbs.com/member-services |
| MKY | Horizon BCBS of New Jersey | https://www.horizonblue.com/ |
| MKZ | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MLA | Wellmark BCBS | https://www.wellmark.com/ |
| MLC | Prefix Not in Use | https://www.bcbs.com/member-services |
| MLE | BCBS of Illinois | https://www.bcbsil.com/ |
| MLG | Highmark BCBS | https://www.highmarkblueshield.com/home/ |
| MLH | Prefix Not in Use | https://www.bcbs.com/member-services |
| MLJ | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MLK | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MLL | Blue Shield of California | https://blueshieldcaplans.com/ |
| MLM | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MLN | Blue Shield of California | https://blueshieldcaplans.com/ |
| MLO | BCBS of Western New York | https://www.bcbswny.com/ |
| MLP | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MLQ | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MLS | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MLT | BCBS of Nebraska | https://www.nebraskablue.com/ |
| MLU | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MLV | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MLW | Prefix Not in Use | https://www.bcbs.com/member-services |
| MLX | Prefix Not in Use | https://www.bcbs.com/member-services |
| MLY | Premera Blue Cross | https://www.premera.com/visitor |
| MLZ | BCBS of Rhode Island | https://www.bcbsri.com/ |
| MMB | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MMD | Premera Blue Cross | https://www.premera.com/visitor |
| MMF | Excellus BCBS of New York | https://www.excellusbcbs.com/ |
| MMG | BCBS of Mississippi | https://www.bcbsms.com/ |
| MMH | Empire BCBS of New York | https://www.empireblue.com/ |
| MMI | Independence Blue Cross | https://www.ibx.com/index.jsp |
| MMJ | BCBS of Michigan | https://www.bcbsm.com/ |
| MMK | BCBS of Illinois | https://www.bcbsil.com/ |
| MMM | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MMN | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MMO | BCBS of Michigan | https://www.bcbsm.com/ |
| MMP | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MMQ | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MMS | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MMT | Prefix Not in Use | https://www.bcbs.com/member-services |
| MMU | BCBS of Illinois | https://www.bcbsil.com/ |
| MMV | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MMW | BCBS of Illinois | https://www.bcbsil.com/ |
| MMX | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MMZ | Wellmark BCBS | https://www.wellmark.com/ |
| MNA | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MNB | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MNC | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MND | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MNE | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MNF | Independence Blue Cross | https://www.ibx.com/index.jsp |
| MNG | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MNH | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MNI | Prefix Not in Use | https://www.bcbs.com/member-services |
| MNK | BCBS of Michigan | https://www.bcbsm.com/ |
| MNL | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MNM | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MNN | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MNO | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MNP | Blue Shield of California | https://blueshieldcaplans.com/ |
| MNQ | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MNR | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MNS | Anthem BCBS of Kentucky | https://www.anthem.com/individual-and-family/health-insurance/kentucky/ |
| MNT | BCBS of Illinois | https://www.bcbsil.com/ |
| MNU | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MNW | Premera Blue Cross | https://www.premera.com/visitor |
| MNX | BCBS of Illinois | https://www.bcbsil.com/ |
| MNZ | Wellmark BCBS | https://www.wellmark.com/ |
| MOA | Prefix Not in Use | https://www.bcbs.com/member-services |
| MOC | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MOD | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MOE | BCBS of Illinois | https://www.bcbsil.com/ |
| MOF | Blue Shield of California | https://blueshieldcaplans.com/ |
| MOG | BCBS of Western New York | https://www.bcbswny.com/ |
| MOH | Prefix Not in Use | https://www.bcbs.com/member-services |
| MOI | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MOJ | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MOK | Independence Blue Cross | https://www.ibx.com/index.jsp |
| MOL | Prefix Not in Use | https://www.bcbs.com/member-services |
| MOM | Prefix Not in Use | https://www.bcbs.com/member-services |
| MOR | Premera Blue Cross | https://www.premera.com/visitor |
| MOT | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MOW | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MOX | BCBS of Illinois | https://www.bcbsil.com/ |
| MOY | Wellmark BCBS | https://www.wellmark.com/ |
| MPA | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MPC | BCBS of Rhode Island | https://www.bcbsri.com/ |
| MPD | BCBS of Texas | https://www.bcbstx.com/ |
| MPE | BCBS of Michigan | https://www.bcbsm.com/ |
| MPF | Excellus BCBS of New York | https://www.excellusbcbs.com/ |
| MPH | Empire BCBS of New York | https://www.empireblue.com/ |
| MPI | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MPL | BCBS of Illinois | https://www.bcbsil.com/ |
| MPM | Prefix Not in Use | https://www.bcbs.com/member-services |
| MPO | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MPP | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MPQ | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MPR | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MPS | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MPT | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MPU | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MPV | Prefix Not in Use | https://www.bcbs.com/member-services |
| MPW | Prefix Not in Use | https://www.bcbs.com/member-services |
| MPX | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MQA | BCBS of Michigan | https://www.bcbsm.com/ |
| MQC | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MQD | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MQF | BCBS of Western New York | https://www.bcbswny.com/ |
| MQH | BCBS of Michigan | https://www.bcbsm.com/ |
| MQI | Wellmark BCBS | https://www.wellmark.com/ |
| MQJ | BCBS of Michigan | https://www.bcbsm.com/ |
| MQK | BCBS of Michigan | https://www.bcbsm.com/ |
| MQL | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MQM | BCBS of Michigan | https://www.bcbsm.com/ |
| MQN | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MQO | BCBS of Michigan | https://www.bcbsm.com/ |
| MQP | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MQR | Highmark BCBS | https://www.highmarkblueshield.com/home/ |
| MQS | Prefix Not in Use | https://www.bcbs.com/member-services |
| MQT | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MQU | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MQW | BCBS of Michigan | https://www.bcbsm.com/ |
| MQX | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MQY | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MQZ | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MRA | Prefix Not in Use | https://www.bcbs.com/member-services |
| MRC | BCBS of Illinois | https://www.bcbsil.com/ |
| MRE | Wellmark BCBS | https://www.wellmark.com/ |
| MRF | BCBS of Michigan | https://www.bcbsm.com/ |
| MRG | BCBS of Illinois | https://www.bcbsil.com/ |
| MRJ | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MRM | Unknown Assignment | https://www.bcbs.com/ |
| MRN | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MRO | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MRP | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MRQ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MRR | Prefix Not in Use | https://www.bcbs.com/member-services |
| MRS | Wellmark BCBS | https://www.wellmark.com/ |
| MRT | BCBS of Texas | https://www.bcbstx.com/ |
| MRU | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MRV | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MRW | BCBS of Illinois | https://www.bcbsil.com/ |
| MRY | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MRZ | BCBS of Illinois | https://www.bcbsil.com/ |
| MSA | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MSB | Wellmark BCBS | https://www.wellmark.com/ |
| MSC | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MSF | Empire BCBS of New York | https://www.empireblue.com/ |
| MSG | BCBS of Michigan | https://www.bcbsm.com/ |
| MSH | BCBS of Michigan | https://www.bcbsm.com/ |
| MSJ | Premera Blue Cross | https://www.premera.com/visitor |
| MSK | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MSL | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MSM | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MSO | Prefix Not in Use | https://www.bcbs.com/member-services |
| MSP | Premera Blue Cross | https://www.premera.com/visitor |
| MSQ | Premera Blue Cross | https://www.premera.com/visitor |
| MSR | BCBS of Michigan | https://www.bcbsm.com/ |
| MSS | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MST | Premera Blue Cross | https://www.premera.com/visitor |
| MSU | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MSV | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MSW | BCBS of Illinois | https://www.bcbsil.com/ |
| MSX | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MSY | Prefix Not in Use | https://www.bcbs.com/member-services |
| MSZ | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MTB | Wellmark BCBS | https://www.wellmark.com/ |
| MTC | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MTD | Premera Blue Cross | https://www.premera.com/visitor |
| MTE | Blue Shield of California | https://blueshieldcaplans.com/ |
| MTG | Prefix Not in Use | https://www.bcbs.com/member-services |
| MTH | Wellmark BCBS | https://www.wellmark.com/ |
| MTI | Prefix Not in Use | https://www.bcbs.com/member-services |
| MTJ | Blue Cross of Idaho | https://www.bcidaho.com/ |
| MTK | Wellmark BCBS | https://www.wellmark.com/ |
| MTL | BCBS of Texas | https://www.bcbstx.com/ |
| MTM | BCBS of Western New York | https://www.bcbswny.com/ |
| MTN | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MTP | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MTQ | Blue Shield of California | https://blueshieldcaplans.com/ |
| MTR | BCBS of Tennessee | https://www.bcbst.com/get-insurance/index.page |
| MTS | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MTT | Blue Shield of California | https://blueshieldcaplans.com/ |
| MTU | Premera Blue Cross | https://www.premera.com/visitor |
| MTX | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MTY | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MTZ | BCBS of Illinois | https://www.bcbsil.com/ |
| MUA | BCBS of Texas | https://www.bcbstx.com/ |
| MUB | Anthem BCBS of Virginia | https://www.anthem.com/individual-and-family/health-insurance/virginia/ |
| MUC | Wellmark BCBS | https://www.wellmark.com/ |
| MUD | Wellmark BCBS | https://www.wellmark.com/ |
| MUE | Wellmark BCBS | https://www.wellmark.com/ |
| MUH | Blue Cross of Idaho | https://www.bcidaho.com/ |
| MUJ | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MUL | BCBS of Illinois | https://www.bcbsil.com/ |
| MUM | BCBS of Arizona | https://www.azblue.com/individualsandfamilies |
| MUN | BCBS of Illinois | https://www.bcbsil.com/ |
| MUP | BCBS of South Carolina | https://www.southcarolinablues.com/web/public/brands/sc/ |
| MUR | BCBS of Michigan | https://www.bcbsm.com/ |
| MUS | BCBS of Illinois | https://www.bcbsil.com/ |
| MUU | BCBS of Michigan | https://www.bcbsm.com/ |
| MUV | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MUW | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MUX | Wellmark BCBS | https://www.wellmark.com/ |
| MUY | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MUZ | BCBS of Michigan | https://www.bcbsm.com/ |
| MVA | BCBS of Montana | https://www.bcbsmt.com/ |
| MVC | BCBS of Florida | https://www.floridablue.com/ |
| MVD | Premera Blue Cross | https://www.premera.com/visitor |
| MVF | Empire BCBS of New York | https://www.empireblue.com/ |
| MVG | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MVH | Prefix Not in Use | https://www.bcbs.com/member-services |
| MVI | BCBS of Michigan | https://www.bcbsm.com/ |
| MVJ | Blue Shield of California | https://blueshieldcaplans.com/ |
| MVK | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MVL | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MVM | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MVN | Empire BCBS of New York | https://www.empireblue.com/ |
| MVO | Prefix Not in Use | https://www.bcbs.com/member-services |
| MVR | Highmark BCBS | https://www.highmarkblueshield.com/home/ |
| MVS | Prefix Not in Use | https://www.bcbs.com/member-services |
| MVT | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MVU | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MVV | Wellmark BCBS | https://www.wellmark.com/ |
| MVX | BCBS of South Carolina | https://www.southcarolinablues.com/web/public/brands/sc/ |
| MVY | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MVZ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MWA | BCBS of Illinois | https://www.bcbsil.com/ |
| MWB | Prefix Not in Use | https://www.bcbs.com/member-services |
| MWD | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MWE | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MWF | BCBS of Illinois | https://www.bcbsil.com/ |
| MWG | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MWI | Wellmark BCBS | https://www.wellmark.com/ |
| MWJ | Horizon BCBS of New Jersey | https://www.horizonblue.com/ |
| MWK | Horizon BCBS of New Jersey | https://www.horizonblue.com/ |
| MWL | BCBS of Illinois | https://www.bcbsil.com/ |
| MWM | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MWN | BCBS of Illinois | https://www.bcbsil.com/ |
| MWQ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MWR | Unknown Assignment | https://www.bcbs.com/ |
| MWS | Prefix Not in Use | https://www.bcbs.com/member-services |
| MWU | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MWV | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MWW | Anthem BCBS of Nevada | https://www.anthem.com/individual-and-family/health-insurance/nevada/ |
| MWX | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MWY | Prefix Not in Use | https://www.bcbs.com/member-services |
| MXA | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MXB | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MXC | Prefix Not in Use | https://www.bcbs.com/member-services |
| MXD | BCBS of Texas | https://www.bcbstx.com/ |
| MXE | BCBS of Texas | https://www.bcbstx.com/ |
| MXF | Empire BCBS of New York | https://www.empireblue.com/ |
| MXH | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MXI | Blue Shield of California | https://blueshieldcaplans.com/ |
| MXJ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MXK | Capital Blue Cross | https://www.capbluecross.com/ |
| MXM | Wellmark BCBS | https://www.wellmark.com/ |
| MXN | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MXO | Wellmark BCBS | https://www.wellmark.com/ |
| MXP | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MXQ | Empire BCBS of New York | https://www.empireblue.com/ |
| MXR | Anthem Blue Cross of California | https://www.anthem.com/ca/individual-and-family/health-insurance/california/ |
| MXS | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MXT | Prefix Not in Use | https://www.bcbs.com/member-services |
| MXX | Prefix Not in Use | https://www.bcbs.com/member-services |
| MXY | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MXZ | Premera Blue Cross | https://www.premera.com/visitor |
| MYA | Independence Blue Cross | https://www.ibx.com/index.jsp |
| MYC | Prefix Not in Use | https://www.bcbs.com/member-services |
| MYD | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYE | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MYF | Empire BCBS of New York | https://www.empireblue.com/ |
| MYG | Wellmark BCBS | https://www.wellmark.com/ |
| MYH | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYI | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYJ | Prefix Not in Use | https://www.bcbs.com/member-services |
| MYK | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYL | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYM | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MYN | Anthem BCBS of Ohio | https://www.anthem.com/individual-and-family/health-insurance/ohio |
| MYO | Prefix Not in Use | https://www.bcbs.com/member-services |
| MYP | Anthem BCBS of Georgia | https://www.anthem.com/individual-and-family/health-insurance/georgia/ |
| MYQ | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYR | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MYS | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MYT | BCBS of Michigan | https://www.bcbsm.com/ |
| MYV | Prefix Not in Use | https://www.bcbs.com/member-services |
| MYW | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MYX | BCBS of Oklahoma | https://www.bcbsok.com/ |
| MYY | Carefirst BCBS of Maryland | https://individual.carefirst.com/individuals-families/home.page |
| MYZ | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MZA | Wellmark BCBS | https://www.wellmark.com/ |
| MZB | Highmark BCBS | https://www.highmarkbcbs.com/home/ |
| MZC | BCBS of Rhode Island | https://www.bcbsri.com/ |
| MZD | BCBS of Illinois | https://www.bcbsil.com/ |
| MZE | BCBS of Massachusetts | https://home.bluecrossma.com/ |
| MZF | Prefix Not in Use | https://www.bcbs.com/member-services |
| MZG | BCBS of Illinois | https://www.bcbsil.com/ |
| MZJ | Anthem BCBS of Wisconsin | https://www.anthem.com/individual-and-family/wisconsin/ |
| MZL | BCBS of Alabama | https://www.bcbsal.org/web/index.html |
| MZM | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MZN | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MZO | BCBS of Michigan | https://www.bcbsm.com/ |
| MZP | BCBS of Michigan | https://www.bcbsm.com/ |
| MZS | BCBS of North Carolina | https://www.bluecrossnc.com/ |
| MZT | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MZU | BCBS of Florida | https://www.floridablue.com/ |
| MZV | BCBS of Michigan | https://www.bcbsm.com/ |
| MZX | BCBS of Minnesota | https://www.bluecrossmn.com/ |
| MZY | BCBS of Michigan | https://www.bcbsm.com/ |
| MZZ | BCBS of Minnesota | https://www.bluecrossmn.com/ |