| YAK YAM YAN YAO YAR YAW YBZ YCH YCV YDA YDI YEA YEJ YEN YEU YFQ YGT YHC YIO YIQ YLG YMH YMM YMN YNT YNV YPC YPE YPG YPM YPR YQA YQB YQC YQE YQG YQI YQJ YQP YQQ YQS YQU YQX YSE YSH YSI YSK YSP YST YTG YTQ YTY YUC YUE YUU YWR YWS YXI YYE YZH YZM | Alpha Prefix not assigned or unallocated |
| YAF YCS YKX YZB | Anthem Blue-Cross Blue-Shield of Colorado |
| YAA YAH YCT YFV YHH YMW YVY YYL YZK | Anthem Blue-Cross Blue-Shield of Connecticut |
| YCX YGZ YMO YSU | Anthem Blue-Cross Blue-Shield of Georgia |
| YCQ YHJ YHK YHT YHU YHV YRH YRK YVJ YVK YWQ YWU YXH YZD | Anthem Blue-Cross Blue-Shield of Indiana |
| YAC YBL YCJ YDP YZA YZE YZF YZG YZJ YZZ | Anthem Blue-Cross Blue-Shield of Kentucky |
| YBI YCA YCB YCC YCD YCE YCF YCG YCU YMB YMZ YRD YRQ | Anthem Blue-Cross Blue-Shield of Missouri |
| YFA YFB YFC YFD YFF YFG YFH YFI YFJ YFK YFL YFN YFO YFP YFR YFT YFU YFW YFX YFY YFZ YZN YZS YZT YZV | Anthem Blue-Cross Blue-Shield of Nevada |
| YGA YGB YGC YGD YGE YGF YGG YGH YGI YGJ YGK YGL YGM YGN YGO YGP YGQ YGR YGS YGU YGV YGW YGX YZT YZV | Anthem Blue-Cross Blue-Shield of New Hampshire |
| YBK YCK YDQ YEX YFS YKW YKY YOQ YRA YRB YRE YRF YRG YRJ YRL YRM YRN YRO YRP YRR YRS YRT YRU YRX YRY YSF YSY YWL YWO YZI YZO YZQ YZY | Anthem Blue-Cross Blue-Shield of Ohio |
| YAE YMI YRC YRV YRW YRZ YSV YTA YTB YTC YTD YTE YTF YTH YTI YTJ YTK YTL YTM YTN YTO YTP YTR YTS YTT YTU YTV YTW YTX YTZ YVE | Anthem Blue-Cross Blue-Shield of Virginia |
| YCM YOJ YOS YSD YSZ YWI | Anthem Blue-Cross Blue-Shield of Wisconsin |
| YBQ YCL YCY YDH YMQ YMU YMY YNW YSN YSQ YZC YZU | Anthem Bluecross of California |
| YAJ YSM | Blue-Cross Blue-Shield of Alabama |
| YET YFE YMF YNK YNP YNU YUV | Blue-Cross Blue-Shield of Illinois |
| YBA YBB YBC YBD YBE YBF YBG YBH YBJ YBM YBP YBS YBT YBU YBW YBX YJJ YJT YJV YJW | Blue-Cross Blue-Shield of Kansas City |
| YBO YCR YEC YOE YOF YOG YOI YOK YOM YON YOO YOW YOZ YSB YSS | Blue-Cross Blue-Shield of Massachusetts |
| YLI | Blue-Cross Blue-Shield of Michigan |
| YAP YBY YCO YEL YMG YNF YSC | Blue-Cross Blue-Shield of Minnesota |
| YAG YAI YAQ YAS YAU YAX | Blue-Cross Blue-Shield of Mississippi |
| YDC YDD YDE YDF YDG YDJ YDK YDL YDM YDN YDR YDS YDT YDU YDV | Blue-Cross Blue-Shield of Montana |
| YDB YED YEF YEG YEH YEK YEM YEQ YES YEZ YFM YKV YMA YNN YNQ YNX YXN YZL | Blue-Cross Blue-Shield of Nebraska |
| YIA YIB YIC YID YIE YIF YIG YIH YII YIJ YIK YIL YIM YIN YIP YIR YIS YIT YIU YIV YIW YIX YIY YIZ YUT | Blue-Cross Blue-Shield of New Mexico |
| YHI YPA YPD YPF YPH YPI YPJ YPL YPN YPO YPP YPQ YPS YPT YPU YPV YPW YPX YPY YPZ | Blue-Cross Blue-Shield of North Carolina |
| YEI YEO YEP YER YME YNR YQD YQF YQH YQK YQL YQM YQN YQO YQR YQT YQV YQW YQY | Blue-Cross Blue-Shield of North Dakota |
| YUA YUB YUD YUF YUG YUH YUI YUJ YUK YUL YUM YUN YUO YUP YUQ YUR YUS YUW YUX YUY YUZ | Blue-Cross Blue-Shield of Oklahoma |
| YAD YDO YOT YPB YPK YSX YZP | Blue-Cross Blue-Shield of Rhode Island |
| YAV | Blue-Cross Blue-Shield of Tennessee |
| YDX YSR | Blue-Cross Blue-Shield of Texas |
| YDZ YJA YJB YJC YJD YJE YJF YJG YJH YJK YJL YJM YJN YJO YJP YJQ YJR YJS YJU YJX YJY YJZ YOB YQZ YSO YZW YZX | Blue-Cross Blue-Shield of Western New York |
| YWY | Blue-Cross Blue-Shield of Wyoming |
| YCW YMT YMV YSA YSW | Bluecross of Idaho |
| YAT YBR YEB YEE YEV YGY YMS YNA YOA YOC YOU YSG | Blueshield of California |
| YCI YVI YWA YWB YWC YWD YWE YWF YWG YWH YWJ YWK YWM YWN YWP YWT YWV YWW YWZ | Capital Bluecross of Pennsylvania |
| YJI YMR YOX YOY | Carefirst Blue-Cross Blue-Shield(Maryland/District of Columbia/Northern Virginia) |
| YAZ YBN YBV YCZ YDY YEW YEY YLA YLB YLC YLD YLE YLF YLH YLJ YLK YLL YLM YLN YLO YLP YLQ YLR YLS YLT YLU YLV YLW YLX YLY YLZ YMP YWX YXC YXD YXE YXG YXJ YXS YXV YZR | Empire Blue-Cross Blue-Shield of New York |
| YNB YNC YND YNE YNG YNH YNI YNJ YNL YNM YNS | Excellus Blue-Cross Blue-Shield of New York |
| YMD | Highmark Blue-Cross Blue-Shield of Delaware |
| YMC YNO YOD YOH YOL YOV YRI YYA YYB YYC YYD YYF YYG YYH YYI YYJ YYK YYM YYN YYO YYP YYQ YYR YYS YYT YYU YYV YYW YYX YYZ | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| YHA YHB YHD YHE YHF YHG YHL YHN YHO YHP YHQ YHR YHW YHX YHY YHZ YKA YKB YKC YKD YKE YKF YKG YKH YKI YKJ YKK YKL YKM YKO YKQ YKR YKS YKT YKU YKZ YNY YNZ YYY | Horizon Blue-Cross Blue-Shield of New Jersey |
| YXA YXB YXF YXK YXL YXM YXO YXP YXQ YXR YXT YXU YXW YXX YXY YXZ | Independence Bluecross of Philadelphia and Southeastern Pennsylvania |
| YDW YMJ YMK YML YOR YSL | Premera Blue-Cross Blue-Shield of Alaska |
| YMX YSJ | Premera Bluecross of Alaska |
| YAB YAL YCP YOP YVA YVB YVC YVD YVF YVG YVH YVL YVM YVN YVO YVP YVQ YVR YVS YVT YVU YVV YVW YVX YVZ | Regence Blue-Cross Blue-Shield(Oregon/Idaho/Utah/Washington) |
| YAY YCN YHM YHS YKN YKP | Wellmark Blue-Cross Blue-Shield of South Dakota/Iowa |