| KAA | No Prefix Assigned |
| KAB | Wellmark BCBS |
| KAC | BCBS of Texas |
| KAD | BCBS of Michigan |
| KAE | BCBS of Illinois |
| KAF | BCBS of South Carolina |
| KAG | Anthem BCBS of Georgia |
| KAH | Anthem BCBS of Indiana |
| KAI | BCBS of Arizona |
| KAJ | BCBS of Louisiana |
| KAK | BCBS of Western New York |
| KAL | BCBS of Alabama |
| KAM | Wellmark BCBS |
| KAN | No Prefix Assigned |
| KAO | BCBS of Minnesota |
| KAP | Independence Blue Cross |
| KAQ | BCBS of Michigan |
| KAR | No Prefix Assigned |
| KAS | Blue Cross of California |
| KAT | BCBS of Illinois |
| KAU | BCBS of Illinois |
| KAV | Regence BCBS of Oregon |
| KAW | Anthem BCBS of Georgia |
| KAX | Blue Cross of California |
| KAY | Excellus BCBS |
| KAZ | BCBS of Illinois |
| KBA | BCBS of Missouri |
| KBB | Anthem BCBS of Colorado |
| KBC | Anthem BCBS of Virginia |
| KBD | BCBS of South Carolina |
| KBE | Anthem BCBS of Wisconsin |
| KBF | Independence Blue Cross |
| KBG | Regence BCBS of Oregon |
| KBH | Horizon BCBS of New Jersey |
| KBI | Capital Blue Cross |
| KBJ | Empire BCBS |
| KBK | Blue Cross of California |
| KBL | Anthem BCBS of Wisconsin |
| KBM | BCBS of Nebraska |
| KBN | No Prefix Assigned |
| KBO | BCBS of North Carolina |
| KBP | CareFirst BCBS |
| KBQ | CareFirst BCBS |
| KBR | Premera Blue Cross |
| KBS | Anthem BCBS of Wisconsin |
| KBT | Wellmark BCBS |
| KBU | Blue Shield of California |
| KBV | Anthem BCBS of Georgia |
| KBW | Anthem BCBS of Wisconsin |
| KBX | Anthem BCBS of Kentucky |
| KBY | Blue Shield of Northeastern New York |
| KBZ | Blue Cross of California |
| KCA | Wellmark BCBS |
| KCB | Wellmark BCBS |
| KCC | Blue Cross of California |
| KCD | Regence Blue Shield of Washington |
| KCE | Anthem BCBS of Ohio |
| KCF | Blue Cross of California |
| KCG | BCBS of Illinois |
| KCH | Empire BCBS |
| KCI | BCBS of Tennessee |
| KCJ | BCBS of Texas |
| KCK | Anthem BCBS of Ohio |
| KCL | BCBS of Minnesota |
| KCM | Highmark BCBS of Pennsylvania |
| KCN | Highmark BCBS of Pennsylvania |
| KCO | BCBS of Michigan |
| KCP | Blue Cross of California |
| KCQ | Premera Blue Cross |
| KCR | No Prefix Assigned |
| KCS | Wellmark BCBS |
| KCT | Regence BCBS of Oregon |
| KCU | BCBS of Michigan |
| KCV | Wellmark BCBS |
| KCW | BCBS of Michigan |
| KCX | Blue Shield of California |
| KCY | Anthem BCBS of Ohio |
| KCZ | Wellmark BCBS |
| KDA | BCBS of Michigan |
| KDB | BCBS of Michigan |
| KDC | BCBS of South Carolina |
| KDD | BCBS of Nebraska |
| KDE | Blue Shield of California |
| KDF | BCBS of South Carolina |
| KDG | BCBS of Massachusetts |
| KDH | Anthem BCBS of Ohio |
| KDI | Blue Shield of California |
| KDJ | Horizon BCBS of New Jersey |
| KDK | BCBS of Tennessee |
| KDL | BCBS of Kansas City |
| KDM | BCBS of Massachusetts |
| KDN | Anthem BCBS of Wisconsin |
| KDO | BCBS of Michigan |
| KDP | Horizon BCBS of New Jersey |
| KDQ | Horizon BCBS of New Jersey |
| KDR | Highmark BCBS of Pennsylvania |
| KDS | Capital Blue Cross |
| KDT | BCBS of Massachusetts |
| KDU | BCBS of Vermont |
| KDV | Anthem BCBS of Georgia |
| KDW | BCBS of South Carolina |
| KDX | Empire BCBS |
| KDY | CareFirst BCBS |
| KDZ | Blue Shield of California |
| KEA | Wellmark BCBS |
| KEB | Blue Cross of California |
| KEC | Horizon BCBS of New Jersey |
| KED | BCBS of Illinois |
| KEE | Blue Cross of Idaho |
| KEF | Anthem BCBS of Indiana |
| KEG | CareFirst BCBS |
| KEH | CareFirst BCBS |
| KEI | BCBS of Michigan |
| KEJ | Blue Shield of California |
| KEK | Blue Cross of California |
| KEL | BCBS of South Carolina |
| KEM | BCBS of South Carolina |
| KEN | Empire BCBS |
| KEO | Wellmark BCBS |
| KEP | BCBS of Illinois |
| KEQ | Highmark BCBS of Pennsylvania |
| KER | Regence BCBS of Oregon |
| KES | Anthem BCBS of Indiana |
| KET | CareFirst BCBS |
| KEU | CareFirst BCBS |
| KEV | Independence Blue Cross |
| KEW | BCBS of Michigan |
| KEX | BCBS of Illinois |
| KEY | Regence Blue Shield of Washington |
| KEZ | Anthem BCBS of Connect |
| KFA | BCBS of Western New York |
| KFB | Regence Blue Shield of Washington |
| KFC | BCBS of Illinois |
| KFD | Blue Shield of California |
| KFE | Anthem BCBS of Wisconsin |
| KFF | Wellmark BCBS |
| KFG | CareFirst BCBS |
| KFH | BCBS of Nebraska |
| KFI | No Prefix Assigned |
| KFJ | Anthem BCBS of New Hampshire |
| KFK | BCBS of Alabama |
| KFL | Blue Cross of California |
| KFM | Blue Cross of California |
| KFN | BCBS of Illinois |
| KFO | Blue Cross of California |
| KFP | Blue Shield of California |
| KFQ | Anthem BCBS of Ohio |
| KFR | Blue Cross of California |
| KFS | Anthem BCBS of Virginia |
| KFT | BCBS of Illinois |
| KFU | Anthem BCBS of New Hampshire |
| KFV | Anthem BCBS of Indiana |
| KFW | Anthem BCBS of Virginia |
| KFX | CareFirst BCBS |
| KFY | Premera Blue Cross |
| KFZ | BCBS of Minnesota |
| KGA | BCBS of Florida |
| KGB | No Prefix Assigned |
| KGC | BCBS of Florida |
| KGD | Blue Cross of California |
| KGE | Independence Blue Cross |
| KGF | Blue Cross of California |
| KGG | Anthem BCBS of Ohio |
| KGH | BCBS of Louisiana |
| KGI | CareFirst BCBS |
| KGJ | BCBS of South Carolina |
| KGK | Anthem BCBS of Ohio |
| KGL | Anthem BCBS of Nevada |
| KGM | BCBS of Arizona |
| KGN | BCBS of Texas |
| KGO | Blue Shield of California |
| KGP | CareFirst BCBS |
| KGQ | CareFirst BCBS |
| KGR | Anthem BCBS of Ohio |
| KGS | BCBS of Kansas |
| KGT | Anthem BCBS of Ohio |
| KGU | BCBS of Illinois |
| KGV | Anthem BCBS of Ohio |
| KGW | Anthem Blue Cross of California |
| KGX | Anthem BCBS of Virginia |
| KGY | Wellmark BCBS |
| KGZ | Anthem BCBS of Ohio |
| KHA | BCBS of Illinois |
| KHB | BCBS of Alabama |
| KHC | Highmark BCBS of Pennsylvania |
| KHD | Wellmark BCBS |
| KHE | Anthem BCBS of Wisconsin |
| KHF | No Prefix Assigned |
| KHG | Blue Shield of California |
| KHH | BCBS of Alabama |
| KHI | Blue Cross of California |
| KHJ | Empire BCBS |
| KHK | Blue Cross of California |
| KHL | Anthem BCBS of Wisconsin |
| KHM | Independence Blue Cross |
| KHN | Anthem BCBS of Wisconsin |
| KHO | Blue Cross of Idaho |
| KHP | Anthem BCBS of Ohio |
| KHQ | CareFirst BCBS |
| KHR | Capital Blue Cross |
| KHS | Premera Blue Cross |
| KHT | BCBS of Minnesota |
| KHU | Wellmark BCBS |
| KHV | CareFirst BCBS |
| KHW | Blue Cross of California |
| KHX | Anthem BCBS of Wisconsin |
| KHY | Anthem BCBS of Wisconsin |
| KHZ | Wellmark BCBS |
| KIA | Anthem BCBS of Georgia |
| KIB | Anthem BCBS of Georgia |
| KIC | Wellmark BCBS |
| KID | BCBS of Alabama |
| KIE | Anthem BCBS of Georgia |
| KIF | BCBS of Alabama |
| KIG | Empire BCBS |
| KIH | Empire BCBS |
| KII | Blue Shield of California |
| KIJ | BCBS of Alabama |
| KIK | BCBS of Illinois |
| KIL | No Prefix Assigned |
| KIM | BCBS of Western New York |
| KIN | Regence BCBS of Oregon |
| KIO | Empire BCBS |
| KIP | No Prefix Assigned |
| KIQ | No Prefix Assigned |
| KIR | Regence Blue Shield of Washington |
| KIS | Capital Blue Cross |
| KIT | BCBS of Illinois |
| KIU | BCBS of Alabama |
| KIV | Anthem BCBS of Virginia |
| KIW | Anthem BCBS of Virginia |
| KIX | Anthem BCBS of Virginia |
| KIY | BCBS of Western New York |
| KIZ | Blue Cross of California |
| KJA | Anthem BCBS of Georgia |
| KJB | CareFirst BCBS |
| KJC | Blue Cross of California |
| KJD | BCBS of Alabama |
| KJE | Blue Cross of California |
| KJF | BCBS of Illinois |
| KJG | BCBS of Illinois |
| KJH | BCBS of Illinois |
| KJI | BCBS of Missouri |
| KJJ | CareFirst BCBS |
| KJK | Blue Shield of California |
| KJL | Blue Shield of California |
| KJM | BCBS of Illinois |
| KJN | BCBS of Missouri |
| KJO | Anthem BCBS of Ohio |
| KJP | Horizon BCBS of New Jersey |
| KJQ | Anthem BCBS of Missouri |
| KJR | Highmark BCBS of Pennsylvania |
| KJS | No Prefix Assigned |
| KJT | Wellmark BCBS |
| KJU | Anthem BCBS of Missouri |
| KJV | Empire BCBS |
| KJW | BCBS of Illinois |
| KJX | BCBS of Western New York |
| KJY | Highmark BCBS of Pennsylvania |
| KJZ | No Prefix Assigned |
| KKA | BCBS of Alabama |
| KKB | Anthem BCBS of Ohio |
| KKC | BCBS of Michigan |
| KKD | Blue Cross of California |
| KKE | BCBS of Oklahoma |
| KKF | Blue Cross of California |
| KKG | BCBS of Illinois |
| KKH | BCBS of Illinois |
| KKI | Blue Cross of California |
| KKJ | BCBS of Texas |
| KKK | No Prefix Assigned |
| KKL | Wellmark BCBS |
| KKM | Blue Cross of California |
| KKN | Horizon BCBS of New Jersey |
| KKO | BCBS of Michigan |
| KKP | BCBS of Illinois |
| KKQ | BCBS of Arkansas |
| KKR | BCBS of Michigan |
| KKS | Wellmark BCBS |
| KKT | Anthem BCBS of Kentucky |
| KKU | BCBS of Minnesota |
| KKV | Anthem BCBS of Kentucky |
| KKW | Blue Cross of California |
| KKX | BCBS of Nebraska |
| KKY | Premera Blue Cross |
| KKZ | BCBS of Illinois |
| KLA | BCBS of Nebraska |
| KLB | Anthem BCBS of Ohio |
| KLC | Premera Blue Cross |
| KLD | CareFirst BCBS |
| KLE | Anthem BCBS of Ohio |
| KLF | CareFirst BCBS |
| KLG | BCBS of Michigan |
| KLH | BCBS of Nebraska |
| KLI | Anthem BCBS of Georgia |
| KLJ | Premera Blue Cross |
| KLK | Anthem BCBS of Virginia |
| KLL | Empire BCBS |
| KLM | BCBS of Michigan |
| KLN | BCBS of Michigan |
| KLO | Empire BCBS |
| KLP | BCBS of Michigan |
| KLQ | Blue Cross of California |
| KLR | Anthem BCBS of Virginia |
| KLS | BCBS of Minnesota |
| KLT | BCBS of Illinois |
| KLU | CareFirst BCBS |
| KLV | BCBS of Western New York |
| KLW | Blue Cross of California |
| KLX | Horizon BCBS of New Jersey |
| KLY | Blue Cross of California |
| KLZ | Premera Blue Cross |
| KMA | Blue Shield of California |
| KMB | Anthem BCBS of Wisconsin |
| KMC | Wellmark BCBS |
| KMD | Highmark BCBS of Pennsylvania |
| KME | Wellmark BCBS |
| KMF | BCBS of Florida |
| KMG | Blue Shield of Northeastern New York |
| KMH | BCBS of Florida |
| KMI | Blue Shield of California |
| KMJ | Empire BCBS |
| KMK | BCBS of Illinois |
| KML | Blue Cross of California |
| KMM | Highmark BCBS of Pennsylvania |
| KMN | Highmark BCBS of Pennsylvania |
| KMO | Blue Shield of California |
| KMP | BCBS of Nebraska |
| KMQ | Blue Cross of Idaho |
| KMR | Wellmark BCBS |
| KMS | BCBS of South Carolina |
| KMT | BCBS of Michigan |
| KMU | BCBS of Michigan |
| KMV | Anthem BCBS of Maine |
| KMW | Blue Cross of California |
| KMX | Anthem BCBS of Maine |
| KMY | Empire BCBS |
| KMZ | Anthem BCBS of Ohio |
| KNA | Anthem BCBS of Ohio |
| KNB | Highmark BCBS of Pennsylvania |
| KNC | Anthem BCBS of Ohio |
| KND | Anthem BCBS of Ohio |
| KNE | BCBS of Illinois |
| KNF | Independence Blue Cross |
| KNG | Wellmark BCBS |
| KNH | BCBS of Illinois |
| KNI | Anthem BCBS of Missouri |
| KNJ | Blue Shield of California |
| KNK | Anthem BCBS of Georgia |
| KNL | Anthem BCBS of Georgia |
| KNM | No Prefix Assigned |
| KNN | Empire BCBS |
| KNO | Anthem BCBS of Wisconsin |
| KNP | BCBS of Texas |
| KNQ | Blue Cross of California |
| KNR | Blue Cross of California |
| KNS | BCBS of Illinois |
| KNT | Independence Blue Cross |
| KNU | Anthem BCBS of Ohio |
| KNV | CareFirst BCBS |
| KNW | Wellmark BCBS |
| KNX | BCBS of Tennessee |
| KNY | BCBS of Western New York |
| KNZ | BCBS of North Carolina |
| KOA | BCBS of Western New York |
| KOB | Blue Shield of California |
| KOC | BCBS of Massachusetts |
| KOD | BCBS of Western New York |
| KOE | Anthem BCBS of Georgia |
| KOF | Wellmark BCBS |
| KOG | Blue Shield of California |
| KOH | No Prefix Assigned |
| KOI | Independence Blue Cross |
| KOJ | BCBS of Michigan |
| KOK | Blue Shield of California |
| KOL | Anthem BCBS of Ohio |
| KOM | BCBS of Illinois |
| KON | BCBS of Illinois |
| KOO | Blue Cross of Idaho |
| KOP | Anthem BCBS of Wisconsin |
| KOQ | Anthem BCBS of Ohio |
| KOR | BCBS of Michigan |
| KOS | No Prefix Assigned |
| KOT | BCBS of Western New York |
| KOU | BCBS of Michigan |
| KOV | Blue Cross of California |
| KOW | Blue Cross of California |
| KOX | Blue Cross of Idaho |
| KOY | Independence Blue Cross |
| KOZ | BCBS of Michigan |
| KPA | Anthem BCBS of Ohio |
| KPB | BCBS of Massachusetts |
| KPC | Blue Cross of California |
| KPD | Anthem BCBS of Virginia |
| KPE | Anthem BCBS of Georgia |
| KPF | Regence BCBS of Oregon |
| KPG | Anthem BCBS of Ohio |
| KPH | Horizon BCBS of New Jersey |
| KPI | Blue Shield of California |
| KPJ | BCBS of Illinois |
| KPK | BCBS of Texas |
| KPL | BCBS of Nebraska |
| KPM | BCBS of South Carolina |
| KPN | Wellmark BCBS |
| KPO | Blue Shield of California |
| KPP | Anthem BCBS of Virginia |
| KPQ | BCBS of Illinois |
| KPR | Capital Blue Cross |
| KPS | Anthem BCBS of Kentucky |
| KPT | BCBS of Minnesota |
| KPU | Horizon BCBS of New Jersey |
| KPV | BCBS of Illinois |
| KPW | Anthem BCBS of Wisconsin |
| KPX | Anthem BCBS of Wisconsin |
| KPY | Independence Blue Cross |
| KPZ | No Prefix Assigned |
| KQA | Wellmark BCBS |
| KQB | No Prefix Assigned |
| KQC | Blue Shield of California |
| KQD | Horizon BCBS of New Jersey |
| KQE | BCBS of Minnesota |
| KQF | BCBS of Massachusetts |
| KQG | BCBS of Alabama |
| KQH | Wellmark BCBS |
| KQI | BCBS of Rhode Island |
| KQJ | BCBS of North Carolina |
| KQK | Premera Blue Cross |
| KQL | Horizon BCBS of New Jersey |
| KQM | Horizon BCBS of New Jersey |
| KQN | BCBS of Texas |
| KQO | BCBS of Michigan |
| KQP | Anthem BCBS of Wisconsin |
| KQQ | BCBS of Western New York |
| KQR | Anthem BCBS of Wisconsin |
| KQS | Horizon BCBS of New Jersey |
| KQT | Regence BCBS of Oregon |
| KQU | Premera Blue Cross |
| KQV | Regence BCBS of Oregon |
| KQW | BCBS of Michigan |
| KQX | Blue Shield of California |
| KQY | No Prefix Assigned |
| KQZ | No Prefix Assigned |
| KRA | Blue Cross of California |
| KRB | Empire BCBS |
| KRC | Wellmark BCBS |
| KRD | Wellmark BCBS |
| KRE | Anthem BCBS of Ohio |
| KRF | No Prefix Assigned |
| KRG | No Prefix Assigned |
| KRH | Wellmark BCBS |
| KRI | BCBS of Rhode Island |
| KRJ | Wellmark BCBS |
| KRK | No Prefix Assigned |
| KRL | Wellmark BCBS |
| KRM | BCBS of Rhode Island |
| KRN | Anthem BCBS of Missouri |
| KRO | Anthem BCBS of Colorado |
| KRP | BCBS of Illinois |
| KRQ | No Prefix Assigned |
| KRR | BCBS of Illinois |
| KRS | No Prefix Assigned |
| KRT | No Prefix Assigned |
| KRU | Anthem BCBS of Ohio |
| KRV | No Prefix Assigned |
| KRW | Anthem BCBS of Ohio |
| KRX | Anthem BCBS of Wisconsin |
| KRY | No Prefix Assigned |
| KRZ | Blue Cross of California |
| KSA | BCBS of Kansas |
| KSB | Regence Blue Shield of Washington |
| KSC | BCBS of Michigan |
| KSD | Independence Blue Cross |
| KSE | BCBS of Kansas |
| KSF | Blue Cross of California |
| KSG | Anthem BCBS of Ohio |
| KSH | Empire BCBS |
| KSI | BCBS of Tennessee |
| KSJ | BCBS of South Carolina |
| KSK | BCBS of Texas |
| KSL | BCBS of Massachusetts |
| KSM | BCBS of Massachusetts |
| KSN | Empire BCBS |
| KSO | BCBS of Massachusetts |
| KSP | BCBS of Michigan |
| KSQ | BCBS of Texas |
| KSR | CareFirst BCBS |
| KSS | BCBS of Texas |
| KST | BCBS of Arizona |
| KSU | Anthem BCBS of Ohio |
| KSV | Blue Cross of California |
| KSW | BCBS of Tennessee |
| KSX | Anthem BCBS of Georgia |
| KSY | Blue Cross of California |
| KSZ | BCBS of Tennessee |
| KTA | Blue Cross of California |
| KTB | Wellmark BCBS |
| KTC | Highmark BCBS of Pennsylvania |
| KTD | BCBS of Western New York |
| KTE | BCBS of Western New York |
| KTF | Blue Shield of California |
| KTG | Anthem BCBS of Wisconsin |
| KTH | BCBS of Illinois |
| KTI | Blue Shield of California |
| KTJ | BCBS of Illinois |
| KTK | BCBS of Nebraska |
| KTL | Wellmark BCBS |
| KTM | CareFirst BCBS |
| KTN | Premera Blue Cross |
| KTO | BCBS of Arizona |
| KTP | Blue Shield of California |
| KTQ | Premera Blue Cross |
| KTR | Anthem BCBS of Virginia |
| KTS | Anthem BCBS of Ohio |
| KTT | Anthem BCBS of Georgia |
| KTU | BCBS of Illinois |
| KTV | BCBS of Illinois |
| KTW | Anthem BCBS of Georgia |
| KTX | Anthem BCBS of Georgia |
| KTY | BCBS of Vermont |
| KTZ | BCBS of Texas |
| KUA | CareFirst BCBS |
| KUB | BCBS of Tennessee |
| KUC | BCBS of Illinois |
| KUD | No Prefix Assigned |
| KUE | Blue Shield of California |
| KUF | Wellmark BCBS |
| KUG | Horizon BCBS of New Jersey |
| KUH | Anthem BCBS of Virginia |
| KUI | BCBS of Michigan |
| KUJ | Anthem BCBS of Ohio |
| KUK | Horizon BCBS of New Jersey |
| KUL | BCBS of Illinois |
| KUM | BCBS of Arkansas |
| KUN | Regence BCBS of Oregon |
| KUO | BCBS of Michigan |
| KUP | BCBS of Rhode Island |
| KUQ | BCBS of Minnesota |
| KUR | BCBS of Illinois |
| KUS | BCBS of South Carolina |
| KUT | BCBS of South Carolina |
| KUU | Anthem BCBS of Ohio |
| KUV | Anthem BCBS of Nevada |
| KUW | BCBS of Illinois |
| KUX | No Prefix Assigned |
| KUY | Highmark BCBS of Pennsylvania |
| KUZ | No Prefix Assigned |
| KVA | BCBS of Illinois |
| KVB | BCBS of Alabama |
| KVC | Wellmark BCBS |
| KVD | BCBS of Alabama |
| KVE | BCBS of Illinois |
| KVF | Wellmark BCBS |
| KVG | BCBS of Minnesota |
| KVH | Capital Blue Cross |
| KVI | BCBS of Tennessee |
| KVJ | BCBS of Illinois |
| KVK | Blue Cross of California |
| KVL | BCBS of Kansas City |
| KVM | Wellmark BCBS |
| KVN | BCBS of Minnesota |
| KVO | BCBS of Minnesota |
| KVP | BCBS of Tennessee |
| KVQ | Wellmark BCBS |
| KVR | Empire BCBS |
| KVS | Premera Blue Cross |
| KVT | Highmark BCBS of Pennsylvania |
| KVU | Anthem BCBS of Georgia |
| KVV | CareFirst BCBS |
| KVW | Anthem BCBS of Wisconsin |
| KVX | BCBS of Massachusetts |
| KVY | Blue Cross of California |
| KVZ | Anthem BCBS of Ohio |
| KWA | BCBS of Michigan |
| KWB | BCBS of North Carolina |
| KWC | BCBS of Tennessee |
| KWD | Blue Cross of California |
| KWE | BCBS of Illinois |
| KWF | BCBS of Kansas City |
| KWG | Wellmark BCBS |
| KWH | Horizon BCBS of New Jersey |
| KWI | Blue Cross of California |
| KWJ | BCBS of Rhode Island |
| KWK | Wellmark BCBS |
| KWL | CareFirst BCBS |
| KWM | Anthem BCBS of Ohio |
| KWN | Blue Cross of California |
| KWO | BCBS of Michigan |
| KWP | BCBS of Massachusetts |
| KWQ | Capital Blue Cross |
| KWR | BCBS of Illinois |
| KWS | BCBS of Illinois |
| KWT | Blue Cross of California |
| KWU | Blue Cross of California |
| KWV | Regence Blue Shield of Washington |
| KWW | CareFirst BCBS |
| KWX | Regence Blue Shield of Washington |
| KWY | Blue Shield of Northeastern New York |
| KWZ | BCBS of Nebraska |
| KXA | BCBS of Western New York |
| KXB | Premera Blue Cross |
| KXC | BCBS of Illinois |
| KXD | BCBS of Western New York |
| KXE | BCBS of Illinois |
| KXF | Blue Shield of Northeastern New York |
| KXG | BCBS of Massachusetts |
| KXH | BCBS of Rhode Island |
| KXI | Blue Cross of California |
| KXJ | Blue Cross of California |
| KXK | BCBS of South Carolina |
| KXL | Anthem BCBS of Wisconsin |
| KXM | Premera Blue Cross |
| KXN | Blue Shield of California |
| KXO | BCBS of Michigan |
| KXP | BCBS of Minnesota |
| KXQ | Anthem BCBS of Missouri |
| KXR | Premera Blue Cross |
| KXS | Wellmark BCBS |
| KXT | Anthem BCBS of Ohio |
| KXU | Anthem BCBS of Virginia |
| KXV | BCBS of Minnesota |
| KXW | BCBS of Illinois |
| KXX | Wellmark BCBS |
| KXY | CareFirst BCBS |
| KXZ | BCBS of Michigan |
| KYA | BCBS of Michigan |
| KYB | BCBS of Illinois |
| KYC | Anthem BCBS of Ohio |
| KYD | BCBS of Michigan |
| KYE | Wellmark BCBS |
| KYF | BCBS of Illinois |
| KYG | Anthem BCBS of Ohio |
| KYH | Anthem BCBS of Ohio |
| KYI | BCBS of Alabama |
| KYJ | Anthem BCBS of Ohio |
| KYK | BCBS of Michigan |
| KYL | Anthem BCBS of Kentucky |
| KYM | BCBS of Michigan |
| KYN | BCBS of Michigan |
| KYO | BCBS of Michigan |
| KYP | BCBS of Michigan |
| KYQ | No Prefix Assigned |
| KYR | Blue Cross of California |
| KYS | Empire BCBS |
| KYT | Anthem BCBS of Kentucky |
| KYU | Anthem BCBS of Ohio |
| KYV | Blue Shield of California |
| KYW | Anthem BCBS of Ohio |
| KYX | BCBS of Alabama |
| KYY | BCBS of South Carolina |
| KYZ | CareFirst BCBS |
| KZA | BCBS of South Carolina |
| KZB | Anthem BCBS of Ohio |
| KZC | BCBS of Alabama |
| KZD | Blue Cross of California |
| KZE | Wellmark BCBS |
| KZF | BCBS of Western New York |
| KZG | BCBS of North Carolina |
| KZH | BCBS of Illinois |
| KZI | Anthem BCBS of Ohio |
| KZJ | Blue Cross of California |
| KZK | CareFirst BCBS |
| KZL | Anthem BCBS of Wisconsin |
| KZM | BCBS of Illinois |
| KZN | BCBS of Texas |
| KZO | BCBS of Michigan |
| KZP | Anthem BCBS of Virginia |
| KZQ | BCBS of Western New York |
| KZR | Horizon BCBS of New Jersey |
| KZS | BCBS of South Carolina |
| KZT | Blue Cross of California |
| KZU | Blue Cross of California |
| KZV | CareFirst BCBS |
| KZW | Blue Cross of California |
| KZX | BCBS of Illinois |
| KZY | BCBS of Michigan |
| KZZ | Anthem BCBS of Georgia |
| K2A | BCBS of Texas |
| K2C | Regence BCBS of Oregon |
| K2D | BCBS of Illinois |
| K2F | BCBS of Illinois |
| K2H | BCBS of Western New York |
| K2N | BCBS of Vermont |
| K2S | Premera Blue Cross |
| K2T | BCBS of Minnesota |
| K2X | BCBS of Illinois |
| K3A | Blue Cross of California |
| K3B | Empire BCBS |
| K3C | Anthem BCBS of Virginia |
| K3G | Regence BCBS of Oregon |
| K3H | Highmark BCBS of Pennsylvania |
| K3S | Premera Blue Cross |
| K3T | Blue Cross of California |
| K3V | Regence Blue Shield of Washington |
| K4A | Empire BCBS |
| K4F | Regence Blue Shield of Washington |
| K4S | BCBS of Massachusetts |
| K5A | Blue Cross of California |
| K5D | BCBS of Illinois |
| K7X | BCBS of Texas |
| K8Y | BCBS of Arizona |
| K8Z | BCBS of Arizona |
