| KAA | Unassigned Prefix |
| KAB | Wellmark |
| KAC | Unassigned Prefix |
| KAD | BCBS Blue Care Network Michigan (MI) |
| KAE | BCBS of Illinois (IL) |
| KAF | BCBS of South Carolina (SC) / Southcarolinablues |
| KAG | Anthem BCBS of Georgia (GA) |
| KAH | Anthem BCBS of Indiana (IN) |
| KAI | BCBS of Arizona (AZ) |
| KAJ | BCBS of Louisiana(LA) |
| KAK | BCBS of Western New York (WNY) |
| KAL | BCBS of Alabama (AL) |
| KAM | Wellmark |
| KAN | Unassigned Prefix |
| KAO | BCBS of Minnesota (MN) |
| KAP | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KAQ | BCBS Blue Care Network Michigan (MI) |
| KAR | BCBS of Kansas City |
| KAS | Unassigned Prefix |
| KAT | BCBS of Illinois (IL) |
| KAU | BCBS of Illinois (IL) |
| KAV | Anthem BCBS of Georgia (GA) |
| KAW | Anthem BCBS of Georgia (GA) |
| KAX | Anthem Blue Cross(BC) of California (CA) |
| KAY | Excellus BCBS of New York (NY) |
| KAZ | BCBS of Illinois (IL) |
| KBA | Anthem BCBS of Missouri (MO) |
| KBB | Anthem BCBS of Colorado (CO) |
| KBC | Anthem BCBS of Virginia (VA) |
| KBD | BCBS of South Carolina (SC) / Southcarolinablues |
| KBE | Anthem BCBS of Wisconsin (WI) |
| KBF | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KBG | Regence BCBS |
| KBH | Horizon BCBS of New Jersey (NJ) |
| KBI | Capital Blue Cross of Pennsylvania (PA) |
| KBJ | Empire BCBS of New York (NY) |
| KBK | Unassigned Prefix |
| KBL | Anthem BCBS of Wisconsin (WI) |
| KBM | BCBS of South Carolina (SC) / Southcarolinablues |
| KBN | Unassigned Prefix |
| KBO | BCBS of North Carolina (NC) |
| KBP | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KBQ | Unassigned Prefix |
| KBR | Premera BCBS of Alaska (AK) |
| KBS | Anthem BCBS of Wisconsin (WI) |
| KBT | Wellmark |
| KBU | BCBS of South Carolina (SC) / Southcarolinablues |
| KBV | Anthem BCBS of Georgia (GA) |
| KBW | Anthem BCBS of Wisconsin (WI) |
| KBX | Anthem BCBS of Kentucky (KY) |
| KBY | Blue shield(BS) of Northeastern New York (NeNY) |
| KBZ | Anthem Blue Cross(BC) of California (CA) |
| KCA | Wellmark |
| KCB | Wellmark |
| KCC | Anthem BCBS of Georgia (GA) |
| KCD | Regence BCBS |
| KCE | Anthem BCBS of Ohio (OH) |
| KCF | Anthem Blue Cross(BC) of California (CA) |
| KCG | BCBS of Illinois (IL) |
| KCH | Empire BCBS of New York (NY) |
| KCI | BCBS of Tennessee (TN) |
| KCJ | BCBS of Texas (TX) |
| KCK | Anthem BCBS of Ohio (OH) |
| KCL | BCBS of Minnesota (MN) |
| KCM | Highmark BCBS of Pennsylvania (PA) |
| KCN | Highmark BCBS of Pennsylvania (PA) |
| KCO | BCBS Blue Care Network Michigan (MI) |
| KCP | BCBS of South Carolina (SC) / Southcarolinablues |
| KCQ | Premera BCBS of Alaska (AK) |
| KCR | Unassigned Prefix |
| KCS | Wellmark |
| KCT | Regence BCBS |
| KCU | BCBS Blue Care Network Michigan (MI) |
| KCV | Wellmark |
| KCW | BCBS Blue Care Network Michigan (MI) |
| KCX | Blue shield(BS) of California (CA) |
| KCY | Anthem BCBS of Ohio (OH) |
| KCZ | Wellmark |
| KDA | BCBS Blue Care Network Michigan (MI) |
| KDB | BCBS Blue Care Network Michigan (MI) |
| KDC | BCBS of Kansas City |
| KDD | Unassigned Prefix |
| KDE | Unassigned Prefix |
| KDF | BCBS of South Carolina (SC) / Southcarolinablues |
| KDG | BCBS of Massachusetts (MA) |
| KDH | Anthem BCBS of Ohio (OH) |
| KDI | Blue shield(BS) of California (CA) |
| KDJ | Horizon BCBS of New Jersey (NJ) |
| KDK | BCBS of Tennessee (TN) |
| KDL | BCBS of Kansas City |
| KDM | BCBS of Massachusetts (MA) |
| KDN | Anthem BCBS of Wisconsin (WI) |
| KDO | BCBS Blue Care Network Michigan (MI) |
| KDP | Horizon BCBS of New Jersey (NJ) |
| KDQ | Horizon BCBS of New Jersey (NJ) |
| KDR | Highmark BCBS of Pennsylvania (PA) |
| KDS | Unassigned Prefix |
| KDT | BCBS of Massachusetts (MA) |
| KDU | BCBS of Vermont (VT) |
| KDV | Anthem BCBS of Georgia (GA) |
| KDW | BCBS of Kansas City |
| KDX | Empire BCBS of New York (NY) |
| KDY | Unassigned Prefix |
| KDZ | Unassigned Prefix |
| KEA | Wellmark |
| KEB | Anthem Blue Cross(BC) of California (CA) |
| KEC | Horizon BCBS of New Jersey (NJ) |
| KED | BCBS of Illinois (IL) |
| KEE | Blue Cross (BC) of Idaho (ID) |
| KEF | Anthem BCBS of Indiana (IN) |
| KEG | Unassigned Prefix |
| KEH | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KEI | BCBS Blue Care Network Michigan (MI) |
| KEJ | Unassigned Prefix |
| KEK | Anthem Blue Cross(BC) of California (CA) |
| KEL | Unassigned Prefix |
| KEM | BCBS of South Carolina (SC) / Southcarolinablues |
| KEN | Unassigned Prefix |
| KEO | Wellmark |
| KEP | BCBS of Illinois (IL) |
| KEQ | Highmark BCBS of Pennsylvania (PA) |
| KER | Regence BCBS |
| KES | Anthem BCBS of Wisconsin (WI) |
| KET | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KEU | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KEV | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KEW | BCBS Blue Care Network Michigan (MI) |
| KEX | BCBS of Illinois (IL) |
| KEY | Unassigned Prefix |
| KEZ | Anthem BCBS of Connecticut (CT) |
| KFA | BCBS of Western New York (WNY) |
| KFB | Regence BCBS |
| KFC | BCBS of Illinois (IL) |
| KFD | Blue shield(BS) of California (CA) |
| KFE | Unassigned Prefix |
| KFF | Unassigned Prefix |
| KFG | Unassigned Prefix |
| KFH | BCBS of Nebraska (NE) |
| KFI | Unassigned Prefix |
| KFJ | Anthem BCBS of New Hampshire (NH) |
| KFK | BCBS of Alabama (AL) |
| KFL | BCBS of South Carolina (SC) / Southcarolinablues |
| KFM BCBS Prefix | Anthem BCBS of Georgia (GA) |
| KFN | Unassigned Prefix |
| KFO | Anthem Blue Cross(BC) of California (CA) |
| KFP | Blue shield(BS) of California (CA) |
| KFQ | Anthem BCBS of Ohio (OH) |
| KFR | Anthem BCBS of Georgia (GA) |
| KFS | Unassigned Prefix |
| KFT | Unassigned Prefix |
| KFU | Anthem BCBS of New Hampshire (NH) |
| KFV | Anthem BCBS of Indiana (IN) |
| KFW | Unassigned Prefix |
| KFX | Unassigned Prefix |
| KFY | Premera BCBS of Alaska (AK) |
| KFZ | Unassigned Prefix |
| KGA | Florida (FL) Blue |
| KGB | BCBS of South Carolina (SC) / Southcarolinablues |
| KGC | Florida (FL) Blue |
| KGD | Anthem Blue Cross(BC) of California (CA) |
| KGE | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KGF | Anthem Blue Cross(BC) of California (CA) |
| KGG | Anthem BCBS of Ohio (OH) |
| KGH | Unassigned Prefix |
| KGI | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KGJ | BCBS of South Carolina (SC) / Southcarolinablues |
| KGK | Anthem BCBS of Ohio (OH) |
| KGL | Anthem BCBS of Nevada (NV) |
| KGM | BCBS of Arizona (AZ) |
| KGN | BCBS of Texas (TX) |
| KGO | Blue shield(BS) of California (CA) |
| KGP | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KGQ | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KGR | Anthem BCBS of Ohio (OH) |
| KGS | BCBS of Kansas |
| KGT | Anthem BCBS of Ohio (OH) |
| KGU | BCBS of Illinois (IL) |
| KGV | Anthem BCBS of Ohio (OH) |
| KGW | Anthem Blue Cross(BC) of California (CA) |
| KGX | Anthem BCBS of Virginia (VA) |
| KGY | Wellmark |
| KGZ | Anthem BCBS of Ohio (OH) |
| KHA | BCBS of Illinois (IL) |
| KHB | BCBS of Alabama (AL) |
| KHC | Highmark BCBS of Pennsylvania (PA) |
| KHD | Wellmark |
| KHE | Anthem BCBS of Wisconsin (WI) |
| KHF | BCBS of South Carolina (SC) / Southcarolinablues |
| KHG | Blue shield(BS) of California (CA) |
| KHH | BCBS of Alabama (AL) |
| KHI | Anthem BCBS of Georgia (GA) |
| KHJ | Anthem BCBS of Wisconsin (WI) |
| KHK | Unassigned Prefix |
| KHL | Anthem BCBS of Wisconsin (WI) |
| KHM | BCBS of South Carolina (SC) / Southcarolinablues |
| KHN | Anthem BCBS of Wisconsin (WI) |
| KHO | Blue Cross (BC) of Idaho (ID) |
| KHP | Anthem BCBS of Ohio (OH) |
| KHQ | Unassigned Prefix |
| KHR | Unassigned Prefix |
| KHS | Premera BCBS of Alaska (AK) |
| KHT | BCBS of Minnesota (MN) |
| KHU | Unassigned Prefix |
| KHV | Anthem BCBS of Georgia (GA) |
| KHW | Unassigned Prefix |
| KHX | Anthem BCBS of Wisconsin (WI) |
| KHY | Anthem BCBS of Wisconsin (WI) |
| KHZ | Wellmark |
| KIA | Anthem BCBS of Georgia (GA) |
| KIB | Anthem BCBS of Indiana (IN) |
| KIC | Unassigned Prefix |
| KID | BCBS of Alabama (AL) |
| KIE | Unassigned Prefix |
| KIF | BCBS of Alabama (AL) |
| KIG | Empire BCBS of New York (NY) |
| KIH | Empire BCBS of New York (NY) |
| KII | Unassigned Prefix |
| KIJ | Unassigned Prefix |
| KIK | BCBS of Illinois (IL) |
| KIL | Unassigned Prefix |
| KIM | BCBS of Western New York (WNY) |
| KIN | Regence BCBS |
| KIO | Empire BCBS of New York (NY) |
| KIP | Unassigned Prefix |
| KIQ | Unassigned Prefix |
| KIR | Regence BCBS |
| KIS | Capital Blue Cross of Pennsylvania (PA) |
| KIT | BCBS of Illinois (IL) |
| KIU | BCBS of Alabama (AL) |
| KIV | Unassigned Prefix |
| KIW | Unassigned Prefix |
| KIX | Blue shield(BS) of California (CA) |
| KIY | BCBS of Western New York (WNY) |
| KIZ | Anthem Blue Cross(BC) of California (CA) |
| KJA | Unassigned Prefix |
| KJB | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KJC | BCBS of South Carolina (SC) / Southcarolinablues |
| KJD | BCBS of Alabama (AL) |
| KJE | Unassigned Prefix |
| KJF | BCBS of Illinois (IL) |
| KJG | BCBS of Illinois (IL) |
| KJH | BCBS of Illinois (IL) |
| KJI | Anthem BCBS of Missouri (MO) |
| KJJ | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KJK | Unassigned Prefix |
| KJL | Unassigned Prefix |
| KJM | Unassigned Prefix |
| KJN | Anthem BCBS of Missouri (MO) |
| KJO | Anthem BCBS of Ohio (OH) |
| KJP | Horizon BCBS of New Jersey (NJ) |
| KJQ | Anthem BCBS of Missouri (MO) |
| KJR | Unassigned Prefix |
| KJS | BCBS of South Carolina (SC) / Southcarolinablues |
| KJT | Unassigned Prefix |
| KJU | Anthem BCBS of Missouri (MO) |
| KJV | Empire BCBS of New York (NY) |
| KJW | BCBS of Illinois (IL) |
| KJX | BCBS of Western New York (WNY) |
| KJY | Unassigned Prefix |
| KJZ | Unassigned Prefix |
| KKA | BCBS of Alabama (AL) |
| KKB | Anthem BCBS of Georgia (GA) |
| KKC | BCBS Blue Care Network Michigan (MI) |
| KKD | Anthem BCBS of Georgia (GA) |
| KKE | BCBS of Oklahoma (OK) |
| KKF | Anthem BCBS of Georgia (GA) |
| KKG | Unassigned Prefix |
| KKH | BCBS of Illinois (IL) |
| KKI | Anthem Blue Cross(BC) of California (CA) |
| KKJ | BCBS of Texas (TX) |
| KKK | Unassigned Prefix |
| KKL | Wellmark |
| KKM | Anthem BCBS of Georgia (GA) |
| KKN | Horizon BCBS of New Jersey (NJ) |
| KKO | BCBS Blue Care Network Michigan (MI) |
| KKP | BCBS of Illinois (IL) |
| KKQ | Unassigned Prefix |
| KKR | BCBS Blue Care Network Michigan (MI) |
| KKS | Wellmark |
| KKT | Anthem BCBS of Kentucky (KY) |
| KKU | BCBS of Minnesota (MN) |
| KKV | Anthem BCBS of Kentucky (KY) |
| KKW | Anthem Blue Cross(BC) of California (CA) |
| KKX | BCBS of Nebraska (NE) |
| KKY | Unassigned Prefix |
| KKZ | Unassigned Prefix |
| KLA | Unassigned Prefix |
| KLB | Anthem BCBS of Ohio (OH) |
| KLC | Unassigned Prefix |
| KLD | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KLE | Anthem BCBS of Ohio (OH) |
| KLF | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KLG | BCBS Blue Care Network Michigan (MI) |
| KLH | BCBS of Nebraska (NE) |
| KLI | Anthem BCBS of Georgia (GA) |
| KLJ | Unassigned Prefix |
| KLK | Anthem BCBS of Virginia (VA) |
| KLL | Empire BCBS of New York (NY) |
| KLM | BCBS Blue Care Network Michigan (MI) |
| KLN | BCBS Blue Care Network Michigan (MI) |
| KLO | Empire BCBS of New York (NY) |
| KLP | BCBS Blue Care Network Michigan (MI) |
| KLQ | Anthem Blue Cross(BC) of California (CA) |
| KLR | Anthem BCBS of Virginia (VA) |
| KLS | BCBS of Minnesota (MN) |
| KLT | BCBS of Illinois (IL) |
| KLU | Unassigned Prefix |
| KLV | BCBS of Western New York (WNY) |
| KLW | Anthem Blue Cross(BC) of California (CA) |
| KLX | Horizon BCBS of New Jersey (NJ) |
| KLY | Anthem Blue Cross(BC) of California (CA) |
| KLZ | Premera BCBS of Alaska (AK) |
| KMA | Blue shield(BS) of California (CA) |
| KMB | Anthem BCBS of Wisconsin (WI) |
| KMC | Unassigned Prefix |
| KMD | Highmark BCBS of Pennsylvania (PA) |
| KME | Wellmark |
| KMF | Florida (FL) Blue |
| KMG | Blue shield(BS) of Northeastern New York (NeNY) |
| KMH | Florida (FL) Blue |
| KMI | Unassigned Prefix |
| KMJ | Empire BCBS of New York (NY) |
| KMK | BCBS of Illinois (IL) |
| KML | Unassigned Prefix |
| KMM | Highmark BCBS of Pennsylvania (PA) |
| KMN | Highmark BCBS of Pennsylvania (PA) |
| KMO | Blue shield(BS) of California (CA) |
| KMP | BCBS of Nebraska (NE) |
| KMQ | Blue Cross (BC) of Idaho (ID) |
| KMR | Wellmark |
| KMS | BCBS of Kansas City |
| KMT | BCBS Blue Care Network Michigan (MI) |
| KMU | BCBS Blue Care Network Michigan (MI) |
| KMV | Anthem BCBS of Maine (ME) |
| KMW | BCBS of South Carolina (SC) / Southcarolinablues |
| KMX | Anthem BCBS of Maine (ME) |
| KMY | Empire BCBS of New York (NY) |
| KMZ | Anthem BCBS of Ohio (OH) |
| KNA | Anthem BCBS of Ohio (OH) |
| KNB | Highmark BCBS of Pennsylvania (PA) |
| KNC | Anthem BCBS of Ohio (OH) |
| KND | Anthem BCBS of Ohio (OH) |
| KNE | BCBS of Illinois (IL) |
| KNF | Unassigned Prefix |
| KNG | Wellmark |
| KNH | Unassigned Prefix |
| KNI | Anthem BCBS of Missouri (MO) |
| KNJ | Blue shield(BS) of California (CA) |
| KNK | Anthem BCBS of Georgia (GA) |
| KNL | Anthem BCBS of Georgia (GA) |
| KNM | Unassigned Prefix |
| KNN | Empire BCBS of New York (NY) |
| KNO | Anthem BCBS of Wisconsin (WI) |
| KNP | BCBS of Texas (TX) |
| KNQ | Anthem Blue Cross(BC) of California (CA) |
| KNR | Anthem Blue Cross(BC) of California (CA) |
| KNS | BCBS of Illinois (IL) |
| KNT | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KNU | Anthem BCBS of Ohio (OH) |
| KNV | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KNW | Wellmark |
| KNX | BCBS of Tennessee (TN) |
| KNY | BCBS of Western New York (WNY) |
| KNZ | BCBS of North Carolina (NC) |
| KOA | BCBS of Western New York (WNY) |
| KOB | Blue shield(BS) of California (CA) |
| KOC | BCBS of Massachusetts (MA) |
| KOD | Unassigned Prefix |
| KOE | Unassigned Prefix |
| KOF | Wellmark |
| KOG | Unassigned Prefix |
| KOH | Unassigned Prefix |
| KOI | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KOJ | BCBS Blue Care Network Michigan (MI) |
| KOK | Unassigned Prefix |
| KOL | Anthem BCBS of Ohio (OH) |
| KOM | BCBS of Illinois (IL) |
| KON | BCBS of Illinois (IL) |
| KOO | Blue Cross (BC) of Idaho (ID) |
| KOP | Anthem BCBS of Wisconsin (WI) |
| KOQ | Anthem BCBS of Ohio (OH) |
| KOR | BCBS Blue Care Network Michigan (MI) |
| KOS | Unassigned Prefix |
| KOT | BCBS of Western New York (WNY) |
| KOU | BCBS Blue Care Network Michigan (MI) |
| KOV | Anthem BCBS of Georgia (GA) |
| KOW | Anthem BCBS of Georgia (GA) |
| KOX | Blue Cross (BC) of Idaho (ID) |
| KOY | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KOZ | BCBS Blue Care Network Michigan (MI) |
| KPA | Anthem BCBS of Ohio (OH) |
| KPB | Unassigned Prefix |
| KPC | Anthem Blue Cross(BC) of California (CA) |
| KPD | Anthem BCBS of Virginia (VA) |
| KPE | Anthem BCBS of Georgia (GA) |
| KPF | Regence BCBS |
| KPG | Anthem BCBS of Ohio (OH) |
| KPH | Horizon BCBS of New Jersey (NJ) |
| KPI | Blue shield(BS) of California (CA) |
| KPJ | BCBS of Illinois (IL) |
| KPK | BCBS of Texas (TX) |
| KPL | Unassigned Prefix |
| KPM | BCBS of Kansas City |
| KPN | Unassigned Prefix |
| KPO | Blue shield(BS) of California (CA) |
| KPP | Anthem BCBS of Virginia (VA) |
| KPQ | Unassigned Prefix |
| KPR | Unassigned Prefix |
| KPS | Anthem BCBS of Kentucky (KY) |
| KPT | BCBS of Minnesota (MN) |
| KPU | Horizon BCBS of New Jersey (NJ) |
| KPV | Unassigned Prefix |
| KPW | Anthem BCBS of Wisconsin (WI) |
| KPX | Anthem BCBS of Wisconsin (WI) |
| KPY | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KPZ | Anthem BCBS of Wisconsin (WI) |
| KQA | Wellmark |
| KQB | Anthem BCBS of Ohio (OH) |
| KQC | Blue shield(BS) of California (CA) |
| KQD | Horizon BCBS of New Jersey (NJ) |
| KQE | Unassigned Prefix |
| KQF | BCBS of Massachusetts (MA) |
| KQG | BCBS of Alabama (AL) |
| KQH | Wellmark |
| KQI | BCBS of Rhode Island (RI) |
| KQJ | BCBS of North Carolina (NC) |
| KQK | Premera BCBS of Alaska (AK) |
| KQL | Horizon BCBS of New Jersey (NJ) |
| KQM | Horizon BCBS of New Jersey (NJ) |
| KQN | BCBS of Texas (TX) |
| KQO | BCBS Blue Care Network Michigan (MI) |
| KQP | Anthem BCBS of Wisconsin (WI) |
| KQQ | BCBS of Western New York (WNY) |
| KQR | Anthem BCBS of Wisconsin (WI) |
| KQS | Horizon BCBS of New Jersey (NJ) |
| KQT | Regence BCBS |
| KQU | Premera BCBS of Alaska (AK) |
| KQV | Unassigned Prefix |
| KQW | BCBS Blue Care Network Michigan (MI) |
| KQX | Unassigned Prefix |
| KQY | Unassigned Prefix |
| KQZ | Unassigned Prefix |
| KRA | Anthem Blue Cross(BC) of California (CA) |
| KRB | Empire BCBS of New York (NY) |
| KRC | Wellmark |
| KRD | Wellmark |
| KRE | Anthem BCBS of Ohio (OH) |
| KRF | Unassigned Prefix |
| KRG | Unassigned Prefix |
| KRH | Wellmark |
| KRI | BCBS Blue Care Network Michigan (MI) |
| KRJ | Wellmark |
| KRK | Unassigned Prefix |
| KRL | Unassigned Prefix |
| KRM | Unassigned Prefix |
| KRN | Anthem BCBS of Missouri (MO) |
| KRO | Anthem BCBS of Ohio (OH) |
| KRP | BCBS of Illinois (IL) |
| KRQ | Unassigned Prefix |
| KRR | BCBS of Illinois (IL) |
| KRS | Unassigned Prefix |
| KRT | Unassigned Prefix |
| KRU | Anthem BCBS of Ohio (OH) |
| KRV | Unassigned Prefix |
| KRW | Anthem BCBS of Ohio (OH) |
| KRX | Anthem BCBS of Wisconsin (WI) |
| KRY | Unassigned Prefix |
| KRZ | Anthem Blue Cross(BC) of California (CA) |
| KSA | BCBS of Kansas |
| KSB | Regence BCBS |
| KSC | BCBS Blue Care Network Michigan (MI) |
| KSD | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| KSE | BCBS of Kansas |
| KSF | Unassigned Prefix |
| KSG | Anthem BCBS of Ohio (OH) |
| KSH | Unassigned Prefix |
| KSI | Unassigned Prefix |
| KSJ | BCBS of Kansas City |
| KSK | BCBS of Texas (TX) |
| KSL | BCBS of Massachusetts (MA) |
| KSM | BCBS of Massachusetts (MA) |
| KSN | Empire BCBS of New York (NY) |
| KSO | BCBS of Massachusetts (MA) |
| KSP | BCBS Blue Care Network Michigan (MI) |
| KSQ | BCBS of Texas (TX) |
| KSR | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KSS | BCBS of Texas (TX) |
| KST | BCBS of Arizona (AZ) |
| KSU | Unassigned Prefix |
| KSV | Unassigned Prefix |
| KSW | BCBS of Tennessee (TN) |
| KSX | Anthem BCBS of Georgia (GA) |
| KSY | Unassigned Prefix |
| KSZ | BCBS of Tennessee (TN) |
| KTA | Anthem Blue Cross(BC) of California (CA) |
| KTB | Wellmark |
| KTC | Highmark BCBS of Pennsylvania (PA) |
| KTD | Anthem BCBS of Kentucky (KY) |
| KTE | BCBS of Western New York (WNY) |
| KTF | Blue shield(BS) of California (CA) |
| KTG | Anthem BCBS of Wisconsin (WI) |
| KTH | BCBS of Illinois (IL) |
| KTI | Blue shield(BS) of California (CA) |
| KTJ | BCBS of Illinois (IL) |
| KTK | BCBS of Nebraska (NE) |
| KTL | Wellmark |
| KTM | Unassigned Prefix |
| KTN | Premera BCBS of Alaska (AK) |
| KTO | BCBS of Arizona (AZ) |
| KTP | Blue shield(BS) of California (CA) |
| KTQ | Premera BCBS of Alaska (AK) |
| KTR | Anthem BCBS of Virginia (VA) |
| KTS | Anthem BCBS of Ohio (OH) |
| KTT | Anthem BCBS of Georgia (GA) |
| KTU | BCBS of Illinois (IL) |
| KTV | BCBS of Illinois (IL) |
| KTW | Anthem BCBS of Georgia (GA) |
| KTX | Anthem BCBS of Georgia (GA) |
| KTY | BCBS of Vermont (VT) |
| KTZ | BCBS of Texas (TX) |
| KUA | Unassigned Prefix |
| KUB | BCBS of Tennessee (TN) |
| KUC | BCBS of Illinois (IL) |
| KUD | Unassigned Prefix |
| KUE | Blue shield(BS) of California (CA) |
| KUF | Wellmark |
| KUG | Horizon BCBS of New Jersey (NJ) |
| KUH | Unassigned Prefix |
| KUI | BCBS Blue Care Network Michigan (MI) |
| KUJ | Anthem BCBS of Ohio (OH) |
| KUK | Horizon BCBS of New Jersey (NJ) |
| KUL | BCBS of Illinois (IL) |
| KUM | Arkansas (AR) Blue Cross |
| KUN | Unassigned Prefix |
| KUO | BCBS Blue Care Network Michigan (MI) |
| KUP | BCBS of Rhode Island (RI) |
| KUQ | Unassigned Prefix |
| KUR | BCBS of Illinois (IL) |
| KUS | BCBS of South Carolina (SC) / Southcarolinablues |
| KUT | BCBS of North Carolina (NC) |
| KUU | Anthem BCBS of Ohio (OH) |
| KUV | Anthem BCBS of Nevada (NV) |
| KUW | BCBS of Illinois (IL) |
| KUX | Unassigned Prefix |
| KUY | Unassigned Prefix |
| KUZ | Unassigned Prefix |
| KVA | BCBS of Illinois (IL) |
| KVB | BCBS of Alabama (AL) |
| KVC | Wellmark |
| KVD | BCBS of Alabama (AL) |
| KVE | Unassigned Prefix |
| KVF | Wellmark |
| KVG | BCBS of Minnesota (MN) |
| KVH | Unassigned Prefix |
| KVI | BCBS of Tennessee (TN) |
| KVJ | Unassigned Prefix |
| KVK | Anthem Blue Cross(BC) of California (CA) |
| KVL | BCBS of Kansas City |
| KVM | Unassigned Prefix |
| KVN | Unassigned Prefix |
| KVO | BCBS of Minnesota (MN) |
| KVP | Unassigned Prefix |
| KVQ | Wellmark |
| KVR | Unassigned Prefix |
| KVS | Premera BCBS of Alaska (AK) |
| KVT | Highmark BCBS of Pennsylvania (PA) |
| KVU | Unassigned Prefix |
| KVV | Unassigned Prefix |
| KVW | Anthem BCBS of Wisconsin (WI) |
| KVX | BCBS of Massachusetts (MA) |
| KVY | Anthem Blue Cross(BC) of California (CA) |
| KVZ | Anthem BCBS of Ohio (OH) |
| KWA | BCBS Blue Care Network Michigan (MI) |
| KWB | BCBS of South Carolina (SC) / Southcarolinablues |
| KWC | Unassigned Prefix |
| KWD | Anthem Blue Cross(BC) of California (CA) |
| KWE | BCBS of Illinois (IL) |
| KWF | BCBS of Kansas City |
| KWG | Wellmark |
| KWH | Horizon BCBS of New Jersey (NJ) |
| KWI | Anthem Blue Cross(BC) of California (CA) |
| KWJ | Unassigned Prefix |
| KWK | Wellmark |
| KWL | Unassigned Prefix |
| KWM | Anthem BCBS of Indiana (IN) |
| KWN | Anthem Blue Cross(BC) of California (CA) |
| KWO | BCBS Blue Care Network Michigan (MI) |
| KWP | BCBS of Massachusetts (MA) |
| KWQ | Capital Blue Cross of Pennsylvania (PA) |
| KWR | BCBS of Illinois (IL) |
| KWS | Unassigned Prefix |
| KWT | Anthem Blue Cross(BC) of California (CA) |
| KWU | Anthem Blue Cross(BC) of California (CA) |
| KWV | Regence BCBS |
| KWW | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KWX | Regence BCBS |
| KWY | Blue shield(BS) of Northeastern New York (NeNY) |
| KWZ | BCBS of Nebraska (NE) |
| KXA | BCBS of Western New York (WNY) |
| KXB | Unassigned Prefix |
| KXC | BCBS of Illinois (IL) |
| KXD | BCBS of Western New York (WNY) |
| KXE | BCBS of Illinois (IL) |
| KXF | Blue shield(BS) of Northeastern New York (NeNY) |
| KXG | BCBS of Massachusetts (MA) |
| KXH | Unassigned Prefix |
| KXI | Anthem Blue Cross(BC) of California (CA) |
| KXJ | Anthem Blue Cross(BC) of California (CA) |
| KXK | Florida (FL) Blue |
| KXL | Anthem BCBS of Wisconsin (WI) |
| KXM | Premera BCBS of Alaska (AK) |
| KXN | Unassigned Prefix |
| KXO | BCBS Blue Care Network Michigan (MI) |
| KXP | BCBS of Minnesota (MN) |
| KXQ | Anthem BCBS of Missouri (MO) |
| KXR | Premera BCBS of Alaska (AK) |
| KXS | Wellmark |
| KXT | Anthem BCBS of Ohio (OH) |
| KXU | Anthem BCBS of Virginia (VA) |
| KXV | BCBS of Minnesota (MN) |
| KXW | BCBS of Illinois (IL) |
| KXX | Wellmark |
| KXY | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KXZ | Unassigned Prefix |
| KYA | BCBS Blue Care Network Michigan (MI) |
| KYB | Unassigned Prefix |
| KYC | Anthem BCBS of Ohio (OH) |
| KYD | BCBS Blue Care Network Michigan (MI) |
| KYE | Wellmark |
| KYF | BCBS of Illinois (IL) |
| KYG | Anthem BCBS of Ohio (OH) |
| KYH | Anthem BCBS of Ohio (OH) |
| KYI | BCBS of Alabama (AL) |
| KYJ | Anthem BCBS of Ohio (OH) |
| KYK | BCBS Blue Care Network Michigan (MI) |
| KYL | Anthem BCBS of Kentucky (KY) |
| KYM | Unassigned Prefix |
| KYN | Unassigned Prefix |
| KYO | BCBS Blue Care Network Michigan (MI) |
| KYP | Unassigned Prefix |
| KYQ | Unassigned Prefix |
| KYR | Anthem Blue Cross(BC) of California (CA) |
| KYS | Empire BCBS of New York (NY) |
| KYT | Anthem BCBS of Kentucky (KY) |
| KYU | Anthem BCBS of Ohio (OH) |
| KYV | Unassigned Prefix |
| KYW | Anthem BCBS of Ohio (OH) |
| KYX | BCBS of Alabama (AL) |
| KYY | Florida (FL) Blue |
| KYZ | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KZA | Unassigned Prefix |
| KZB | Anthem BCBS of Ohio (OH) |
| KZC | BCBS of Alabama (AL) |
| KZD | Anthem Blue Cross(BC) of California (CA) |
| KZE | Wellmark |
| KZF | BCBS of Western New York (WNY) |
| KZG | BCBS of North Carolina (NC) |
| KZH | BCBS of Illinois (IL) |
| KZI | Anthem BCBS of Ohio (OH) |
| KZJ | Unassigned Prefix |
| KZK | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KZL | Anthem BCBS of Wisconsin (WI) |
| KZM | Unassigned Prefix |
| KZN | BCBS of Texas (TX) |
| KZO | BCBS Blue Care Network Michigan (MI) |
| KZP | Anthem BCBS of Virginia (VA) |
| KZQ | BCBS of Western New York (WNY) |
| KZR | Horizon BCBS of New Jersey (NJ) |
| KZS | Florida (FL) Blue |
| KZT | Unassigned Prefix |
| KZU | Anthem Blue Cross(BC) of California (CA) |
| KZV | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| KZW | Unassigned Prefix |
| KZX | BCBS of Illinois (IL) |
| KZY | BCBS Blue Care Network Michigan (MI) |
| KZZ | Anthem BCBS of Georgia (GA) |
