| XBA XBE XBG XBI XBL XBQ XBT XBV XBZ XCE XCN XCV XCY XCZ XFV XHE XHM XIT XIU XIY XIZ XJC XKA XNI XNY XOI XOV XPH XPJ XPL XPM XPT XPY XRF XSC XSG XSI XSK XSP XSQ XSR XSS XTR XUZ XVK XVN XVO XVX XVZ XWA XWB XWW XXL XXX XYI XZB XZF XZG XZI XZJ XZK XZM XZN XZO XZP XZS XZT XZV XZW XZY XZZ | Alpha Prefix not assigned or unallocated |
| XAU XFA XFB XFC XFD XFE XFF XFG XFH XFI XFJ XFK XFL XFM XFN XFO XFP XFS XFT XFW XFX XFY XFZ XRU XTT XWD XWU XWX | Anthem Blue Cross Blue Shield of Colorado |
| XCD XCT XGB XGC XGD XGE XGF XGG XGH XGI XGJ XGK XGL XGM XGN XGO XGP XGR XGS XGT XGV XGY XGZ XHR XRY XTM XVV XWJ XWN XYN XYZ | Anthem Blue Cross Blue Shield of Connecticut |
| XGA XHW XKD XKE XKF XKG XKI XKJ XKK XKL XKN XKO XKP XKR XKS XKT XKU XKV XKW XKX XKY XKZ XRH XRS XSU XTQ XVY | Anthem Blue Cross Blue Shield of Georgia |
| XHJ XPA XPB XPC XPD XPE XPF XPG XPK XPR XPU XPV XPW XPX XRC XUO XWQ XXO | Anthem Blue Cross Blue Shield of Indiana |
| XDY XHB XLJ XPS XTA XTB XTC XTD XTE XTF XTG XTH XTI XTJ XTK XTN XTV | Anthem Blue Cross Blue Shield of Kentucky |
| XJV XMC XRW XVA XVB XVC XVE XVF XVG XVH XVI XVJ XVL XVM XVP XVR XVW | Anthem Blue Cross Blue Shield of Maine |
| XAN XIX XWE XWF | Anthem Blue Cross Blue Shield of Missouri |
| XFR XSO | Anthem Blue Cross Blue Shield of Nevada |
| XFQ XGU XHV XNS | Anthem Blue Cross Blue Shield of New Hampshire |
| XDV XIW XNW XPN XPZ XRB XRE XRG XRL XRO XRV XTL XTU XTZ XWL | Anthem Blue Cross Blue Shield of Ohio |
| XHF XHY XRJ XRK XRN XRQ XSY XTO XTP XYA | Anthem Blue Cross Blue Shield of Virginia |
| XBW XNA XRI XWH XWP | Anthem Blue Cross Blue Shield of Wisconsin |
| XAW XDA XDB XDC XDD XDE XDF XDH XDI XDJ XDK XDL XDM XDN XDO XDP XDQ XDR XDS XDT XDU XDW XDX XDZ XHL XHX XIP XKM XKQ XLO XNL XNX XRP XRR XTS XXJ XYO | Anthem Bluecross of California |
| XCA XCB XCC XCF XCG XCH XCJ XCK XCL XCM XCP XCQ XCR XCS XCU XCW XCX | Arkansas Blue Cross Blue Shield |
| XAA XAB XAC XAD XAE XAF XAG XAI XAJ XAK XAL XAM XAP XAQ XAR XAS XAT XAV XAX XAY XAZ | Blue Cross Blue Shield of Alabama |
| XAH XBB XBC XBD XBF XBH XBK XBM XBN XBO XBP XBR XBS XBU XBX XBY XHK | Blue Cross Blue Shield of Arizona |
| XLA XLB XLC XLD XLE XLF XLG XLH XLI XLK XLL XLM XLN XLP XLQ XLR XLT XLW XLX XLY XLZ | Blue Cross Blue Shield of Hawaii |
| XHS XKC XMW XNB XOA XOB XOC XOD XOE XOF XOG XOH XOJ XOK XOL XOM XON XOO XOP XOQ XOR XOS XOT XOU XOW XOX XOY XOZ XTW XVS XVU XYT | Blue Cross Blue Shield of Illinois |
| XSA XSB XSD XSE XSF XSH XSJ XSL XSM XSN XST XSV XSZ | Blue Cross Blue Shield of Kansas |
| XUA XUB XUC XUD XUE XUF XUG XUH XUI XUJ XUK XUL XUM XUN XUP XUQ XUR XUS XUT XUU XUV XUW XUX XUY | Blue Cross Blue Shield of Louisiana |
| XCI XHN XRA XRX XSX XXA XXB XXC XXD XXE XXF XXG XXH XXI XXK XXM XXN XXP XXQ XXR XXS XXT XXU XXV XXW XXY XXZ | Blue Cross Blue Shield of Massachusetts |
| XYB XYD XYE XYF XYG XYH XYJ XYK XYL XYP XYQ XYR XYS XYU XYV XYW XYX XYY | Blue Cross Blue Shield of Michigan |
| XCO XZA XZC XZD XZE XZH XZL XZQ XZR XZU XZX | Blue Cross Blue Shield of Minnesota |
| XNC | Blue Cross Blue Shield of North Carolina |
| XYC | Blue Cross Blue Shield of Oklahoma |
| XHI XIV XWK XWM | Blue Cross Blue Shield of Rhode Island |
| XTY | Blue Cross Blue Shield of Texas |
| XLS XNG XNQ | Blue Cross Blue Shield of Western New York |
| XHO XID XMA XMB XMD XME XMF XMG XMH XMI XMJ XMK XML XMM XMN XMO XMP XMQ XMR XMS XMT XMU XMV XMX XMY XPO XPQ | Bluecross of Idaho |
| XAO XEA XEB XEC XED XEE XEF XEG XEH XEI XEJ XEK XEL XEM XEN XEO XEP XEQ XER XES XET XEU XEV XEW XEX XEY XEZ XFU XHU XKB XNK XPI XRD XRT XSW | Blueshield of California |
| XRM | Capital Bluecross of Pennsylvania |
| XIA XIB XIC XIE XIF XIG XIH XII XIJ XIK XIL XIM XIN XIO XIQ XIR XIS XRZ XWC XWO XWR XWV XWY XWZ | Carefirst Blue Cross Blue Shield(Maryland/District of Columbia/Northern Virginia) |
| XBJ XGQ XGW XGX XHZ XLU XNU XNZ XWG | Empire Blue Cross Blue Shield of New York |
| XJA XJB XJD XJE XJF XJG XJH XJI XJJ XJK XJL XJM XJN XJO XJP XJQ XJR XJS XJT XJU XJW XJX XJY XJZ | Florida Blue |
| XHA XHC XHD XHG XHH XHP | Highmark Blue Cross Blue Shield of Delaware |
| XVQ | Horizon Blue Cross Blue Shield of New Jersey |
| XDG XHQ XPP | Independence Bluecross of Philadelphia and Southeastern Pennsylvania |
| XHT XKH XVD XWT | Premera Blue Cross Blue Shield of Alaska |
| XND XNE XNF XNH XNJ XNM XNN XNO XNP XNR XNT XNV XVT XYM | Regence Blue Cross Blue Shield(Oregon/Idaho/Utah/Washington) |
| XLV XMZ XQA XQB XQC XQD XQE XQF XQG XQH XQI XQJ XQK XQL XQM XQN XQO XQP XQQ XQR XQS XQT XQU XQV XQW XQX XQY XQZ XTX XWI XWS | Wellmark Blue Cross Blue Shield of South Dakota/Iowa |