| TAA | Highmark BCBS of Pennsylvania |
| TAB | Anthem Blue-Cross |
| TAC | Blue-Shield of California |
| TAD | Anthem BCBS of Connecticut |
| TAE | Anthem BCBS of Colorado |
| TAF | BCBS of Illinois |
| TAG | Anthem BCBS of Ohio |
| TAH | Premera BCBS of Alaska |
| TAI | Anthem Blue-Cross |
| TAJ | BCBS of Illinois |
| TAK | Wellmark BCBS |
| TAL | BCBS of Minnesota |
| TAM | Anthem BCBS of Virginia |
| TAN | No Prefix Assigned |
| TAO | No Prefix Assigned |
| TAP | Premera BCBS of Alaska |
| TAQ | BCBS of Western New York |
| TAR | Anthem BCBS of Ohio |
| TAS | Anthem BCBS of Wisconsin |
| TAT | No Prefix Assigned |
| TAU | BCBS of Massachusetts |
| TAV | Florida-Blue |
| TAW | Anthem BCBS of New Hampshire |
| TAX | No Prefix Assigned |
| TAY | BCBS of North Carolina |
| TAZ | No Prefix Assigned |
| TBA | BCBS of Michigan |
| TBB | Anthem BCBS of Wisconsin |
| TBC | BCBS of Texas |
| TBD | BCBS of South Carolina |
| TBE | BCBS of Illinois |
| TBF | Anthem BCBS of Missouri |
| TBG | Horizon BCBS of New Jersey |
| TBH | Anthem BCBS of Missouri |
| TBI | Anthem BCBS of Virginia |
| TBJ | BCBS of Massachusetts |
| TBK | BCBS of Illinois |
| TBL | No Prefix Assigned |
| TBM | Highmark BCBS of Pennsylvania |
| TBN | No Prefix Assigned |
| TBO | Anthem BCBS of Missouri |
| TBP | BCBS of Michigan |
| TBQ | Anthem BCBS of Wisconsin |
| TBR | BCBS of Michigan |
| TBS | BCBS of Kansas City |
| TBT | Anthem Blue-Cross |
| TBU | No Prefix Assigned |
| TBV | BCBS of Minnesota |
| TBW | Anthem BCBS of Virginia |
| TBX | BCBS of Michigan |
| TBY | Florida-Blue |
| TBZ | BCBS of Massachusetts |
| TCA | BCBS of Alabama |
| TCB | Anthem BCBS of Ohio |
| TCC | BCBS of Illinois |
| TCD | No Prefix Assigned |
| TCE | Anthem BCBS of Ohio |
| TCF | Anthem BCBS of Ohio |
| TCG | BCBS of Texas |
| TCH | Anthem BCBS of Ohio |
| TCI | BCBS of Massachusetts |
| TCJ | BCBS of Massachusetts |
| TCK | BCBS of Massachusetts |
| TCL | Anthem BCBS of Georgia |
| TCM | BCBS of Michigan |
| TCN | No Prefix Assigned |
| TCO | BCBS of North Carolina |
| TCP | BCBS of Texas |
| TCQ | Blue-Shield of California |
| TCR | BCBS of Texas |
| TCS | Anthem BCBS of Kentucky |
| TCT | Anthem BCBS of Ohio |
| TCU | No Prefix Assigned |
| TCV | Florida-Blue |
| TCW | No Prefix Assigned |
| TCX | Blue-Shield of California |
| TCY | No Prefix Assigned |
| TCZ | No Prefix Assigned |
| TDA | BCBS of Illinois |
| TDB | Blue-Cross of Idaho |
| TDC | Highmark BCBS of Pennsylvania |
| TDD | No Prefix Assigned |
| TDE | BCBS of Minnesota |
| TDF | No Prefix Assigned |
| TDG | Anthem BCBS of Nevada |
| TDH | No Prefix Assigned |
| TDI | Blue-Shield of California |
| TDJ | BCBS of Michigan |
| TDK | BCBS of North Carolina |
| TDL | Highmark BCBS of Pennsylvania |
| TDM | Credence BCBS |
| TDN | Anthem BCBS of Ohio |
| TDO | Anthem BCBS of Virginia |
| TDP | Anthem BCBS of Wisconsin |
| TDQ | BCBS of Michigan |
| TDR | No Prefix Assigned |
| TDS | No Prefix Assigned |
| TDT | Premera BCBS of Alaska |
| TDU | No Prefix Assigned |
| TDV | BCBS of Michigan |
| TDW | No Prefix Assigned |
| TDX | Blue-Shield of California |
| TDY | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TDZ | Anthem BCBS of Georgia |
| TEA | BCBS of Illinois |
| TEB | Horizon BCBS of New Jersey |
| TEC | BCBS of Texas |
| TED | No Prefix Assigned |
| TEE | No Prefix Assigned |
| TEF | Blue-Shield of California |
| TEG | Carefirst BCBS |
| TEH | Blue-Shield of California |
| TEI | Anthem BCBS of Ohio |
| TEJ | BCBS of Western New York |
| TEK | BCBS of Illinois |
| TEL | BCBS of Alabama |
| TEM | No Prefix Assigned |
| TEN | No Prefix Assigned |
| TEO | No Prefix Assigned |
| TEP | BCBS of Illinois |
| TEQ | BCBS of Alabama |
| TER | Carefirst BCBS |
| TES | Blue-Shield of California |
| TET | BCBS of South Carolina |
| TEU | No Prefix Assigned |
| TEV | BCBS of Michigan |
| TEW | BCBS of Illinois |
| TEX | BCBS of Texas |
| TEY | No Prefix Assigned |
| TEZ | No Prefix Assigned |
| TFA | No Prefix Assigned |
| TFB | Regence BCBS |
| TFC | Regence BCBS |
| TFD | BCBS of Illinois |
| TFE | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TFF | Anthem BCBS of Ohio |
| TFG | Carefirst BCBS |
| TFH | BCBS of Tennessee |
| TFI | Blue-Cross of Idaho |
| TFJ | Anthem BCBS of Connecticut |
| TFK | No Prefix Assigned |
| TFL | BCBS of Minnesota |
| TFM | BCBS of Minnesota |
| TFN | No Prefix Assigned |
| TFO | No Prefix Assigned |
| TFP | Carefirst BCBS |
| TFQ | No Prefix Assigned |
| TFR | BCBS of Alabama |
| TFS | No Prefix Assigned |
| TFT | No Prefix Assigned |
| TFU | Carefirst BCBS |
| TFV | No Prefix Assigned |
| TFW | No Prefix Assigned |
| TFX | Highmark BCBS of Pennsylvania |
| TFY | BCBS of Illinois |
| TFZ | BCBS of Illinois |
| TGA | Empire BCBS of New York |
| TGB | BCBS of Texas |
| TGC | Anthem BCBS of Ohio |
| TGD | BCBS of Western New York |
| TGE | Empire BCBS of New York |
| TGF | BCBS of Texas |
| TGG | No Prefix Assigned |
| TGH | BCBS of Illinois |
| TGI | BCBS of Western New York |
| TGJ | Wellmark BCBS |
| TGK | No Prefix Assigned |
| TGL | BCBS of Arizona |
| TGM | Florida Explore-My-Plan |
| TGN | BCBS of Michigan |
| TGO | Regence BCBS |
| TGP | No Prefix Assigned |
| TGQ | Anthem BCBS of Wisconsin |
| TGR | Anthem BCBS of Missouri |
| TGS | Empire BCBS of New York |
| TGT | No Prefix Assigned |
| TGU | No Prefix Assigned |
| TGV | No Prefix Assigned |
| TGW | Horizon BCBS of New Jersey |
| TGX | Blue-Shield of California |
| TGY | No Prefix Assigned |
| TGZ | Anthem BCBS of Colorado |
| THA | Anthem BCBS of Kentucky |
| THB | Carefirst BCBS |
| THC | Carefirst BCBS |
| THD | Wellmark BCBS |
| THE | Carefirst BCBS |
| THF | BCBS of Texas |
| THG | BCBS of Alabama |
| THH | Carefirst BCBS |
| THI | No Prefix Assigned |
| THJ | Anthem BCBS of Wisconsin |
| THK | No Prefix Assigned |
| THL | No Prefix Assigned |
| THM | Florida-Blue |
| THN | Wellmark BCBS |
| THO | No Prefix Assigned |
| THP | No Prefix Assigned |
| THQ | Florida-Blue |
| THR | Regence BCBS |
| THS | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| THT | Florida-Blue |
| THU | Anthem Blue-Cross |
| THV | BCBS of Alabama |
| THW | Blue-Shield of California |
| THX | BCBS of Tennessee |
| THY | Anthem BCBS of Virginia |
| THZ | Anthem BCBS of Virginia |
| TIA | No Prefix Assigned |
| TIB | Carefirst BCBS |
| TIC | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TID | BCBS of Western New York |
| TIE | BCBS of Michigan |
| TIF | BCBS of Massachusetts |
| TIG | BCBS of Nebraska |
| TIH | No Prefix Assigned |
| TII | No Prefix Assigned |
| TIJ | BCBS of North Carolina |
| TIK | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TIL | No Prefix Assigned |
| TIM | Regence BCBS |
| TIN | BCBS of South Carolina |
| TIO | Anthem BCBS of Ohio |
| TIP | Anthem BCBS of Virginia |
| TIQ | No Prefix Assigned |
| TIR | Anthem BCBS of Virginia |
| TIS | Anthem BCBS of Georgia |
| TIT | No Prefix Assigned |
| TIU | BCBS of Michigan |
| TIV | Regence BCBS |
| TIW | BCBS of Illinois |
| TIX | Blue-Shield of California |
| TIY | BCBS of Michigan |
| TIZ | Blue-Shield of California |
| TJA | Anthem BCBS of Virginia |
| TJB | BCBS of Texas |
| TJC | No Prefix Assigned |
| TJD | BCBS of Michigan |
| TJE | No Prefix Assigned |
| TJF | BCBS of Texas |
| TJG | No Prefix Assigned |
| TJH | Anthem BCBS of Ohio |
| TJI | No Prefix Assigned |
| TJJ | BCBS of Massachusetts |
| TJK | BCBS of Texas |
| TJL | No Prefix Assigned |
| TJM | No Prefix Assigned |
| TJN | BCBS of Alabama |
| TJO | No Prefix Assigned |
| TJP | BCBS of Michigan |
| TJQ | Blue-Shield of California |
| TJR | BCBS of Nebraska |
| TJS | Anthem Blue-Cross |
| TJT | No Prefix Assigned |
| TJU | Horizon BCBS of New Jersey |
| TJV | Blue-Shield of California |
| TJW | BCBS of Massachusetts |
| TJX | BCBS of Massachusetts |
| TJY | BCBS of Texas |
| TJZ | BCBS of Illinois |
| TKA | BCBS of Michigan |
| TKB | BCBS of Mississippi |
| TKC | Anthem BCBS of Ohio |
| TKD | Premera BCBS of Alaska |
| TKE | BCBS of Illinois |
| TKF | Regence BCBS |
| TKG | BCBS of Illinois |
| TKH | BCBS of Illinois |
| TKI | Anthem BCBS of Ohio |
| TKJ | No Prefix Assigned |
| TKK | BCBS of Illinois |
| TKL | BCBS of Texas |
| TKM | No Prefix Assigned |
| TKN | Wellmark BCBS |
| TKO | BCBS of Rhode Island |
| TKP | BCBS of Massachusetts |
| TKQ | No Prefix Assigned |
| TKR | No Prefix Assigned |
| TKS | No Prefix Assigned |
| TKT | BCBS of Texas |
| TKU | No Prefix Assigned |
| TKV | No Prefix Assigned |
| TKW | BCBS of Michigan |
| TKX | BCBS of Texas |
| TKY | BCBS of Michigan |
| TKZ | BCBS of Michigan |
| TLA | Blue-Shield of California |
| TLB | No Prefix Assigned |
| TLC | No Prefix Assigned |
| TLD | BCBS of Massachusetts |
| TLE | BCBS of Illinois |
| TLF | BCBS of North Carolina |
| TLG | No Prefix Assigned |
| TLH | Horizon BCBS of New Jersey |
| TLI | BCBS of Massachusetts |
| TLJ | BCBS of Alabama |
| TLK | BCBS of Michigan |
| TLL | Anthem Blue-Cross |
| TLM | Blue-Shield of California |
| TLN | BCBS of Illinois |
| TLO | BCBS of Illinois |
| TLP | Anthem BCBS of Connecticut |
| TLQ | Anthem BCBS of Ohio |
| TLR | BCBS of Illinois |
| TLS | No Prefix Assigned |
| TLT | BCBS of Illinois |
| TLU | BCBS of Illinois |
| TLV | BCBS of Rhode Island |
| TLW | BCBS of Western New York |
| TLX | BCBS of Illinois |
| TLY | BCBS of Western New York |
| TLZ | No Prefix Assigned |
| TMA | Blue-Shield of California |
| TMB | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TMC | BCBS of Louisiana |
| TMD | BCBS of Texas |
| TME | Blue-Cross of Idaho |
| TMF | No Prefix Assigned |
| TMG | BCBS of Alabama |
| TMH | BCBS of Michigan |
| TMI | BCBS of Massachusetts |
| TMJ | BCBS of Illinois |
| TMK | BCBS of Texas |
| TML | BCBS of Illinois |
| TMM | BCBS of Texas |
| TMN | Anthem Blue-Cross |
| TMO | BCBS of North Dakota |
| TMP | Premera Blue-Cross of Alaska |
| TMQ | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TMR | Anthem BCBS of Kentucky |
| TMS | BCBS of Illinois |
| TMT | Anthem BCBS of Missouri |
| TMU | Horizon BCBS of New Jersey |
| TMV | BCBS of Illinois |
| TMW | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TMX | BCBS of Alabama |
| TMY | Regence BCBS |
| TMZ | BCBS of Arizona |
| TNA | BCBS of South Carolina |
| TNB | No Prefix Assigned |
| TNC | No Prefix Assigned |
| TND | No Prefix Assigned |
| TNE | Wellmark BCBS |
| TNF | Anthem BCBS of Ohio |
| TNG | Regence BCBS |
| TNH | No Prefix Assigned |
| TNI | BCBS of Michigan |
| TNJ | No Prefix Assigned |
| TNK | Anthem BCBS of Wisconsin |
| TNL | BCBS of Minnesota |
| TNM | No Prefix Assigned |
| TNN | Arkansas BCBS |
| TNO | BCBS of North Carolina |
| TNP | No Prefix Assigned |
| TNQ | Anthem BCBS of Ohio |
| TNR | BCBS of Massachusetts |
| TNS | Excellus BCBS of New York |
| TNT | No Prefix Assigned |
| TNU | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TNV | Empire BCBS of New York |
| TNW | Wellmark BCBS |
| TNX | BCBS of North Carolina |
| TNY | Excellus BCBS of New York |
| TNZ | BCBS of Tennessee |
| TOA | Anthem BCBS of Kentucky |
| TOB | Carefirst BCBS |
| TOC | Arkansas BCBS |
| TOD | BCBS of Alabama |
| TOE | BCBS of Kansas |
| TOF | No Prefix Assigned |
| TOG | Regence BCBS |
| TOH | Anthem BCBS of Ohio |
| TOI | No Prefix Assigned |
| TOJ | No Prefix Assigned |
| TOK | BCBS of North Carolina |
| TOL | BCBS of Minnesota |
| TOM | Wellmark BCBS |
| TON | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TOO | Blue-Shield of California |
| TOP | No Prefix Assigned |
| TOQ | BCBS of Minnesota |
| TOR | No Prefix Assigned |
| TOS | No Prefix Assigned |
| TOT | Anthem BCBS of Georgia |
| TOU | BCBS of Michigan |
| TOV | BCBS of Michigan |
| TOW | No Prefix Assigned |
| TOX | BCBS of Minnesota |
| TOY | BCBS of Michigan |
| TOZ | No Prefix Assigned |
| TPA | No Prefix Assigned |
| TPB | BCBS of Michigan |
| TPC | Wellmark BCBS |
| TPD | Carefirst BCBS |
| TPE | Anthem BCBS of Kentucky |
| TPF | Anthem Blue-Cross |
| TPG | BCBS of Rhode Island |
| TPH | Wellmark BCBS |
| TPI | BCBS of Illinois |
| TPJ | No Prefix Assigned |
| TPK | No Prefix Assigned |
| TPL | Anthem BCBS of Kentucky |
| TPM | BCBS of Michigan |
| TPN | Anthem BCBS of Ohio |
| TPO | No Prefix Assigned |
| TPP | No Prefix Assigned |
| TPQ | Wellmark BCBS |
| TPR | Wellmark BCBS |
| TPS | Anthem Blue-Cross |
| TPT | Excellus BCBS of New York |
| TPU | Anthem BCBS of Virginia |
| TPV | BCBS of Illinois |
| TPW | Regence BCBS |
| TPX | Anthem BCBS of Kentucky |
| TPY | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TPZ | No Prefix Assigned |
| TQA | Premera Blue-Cross of Alaska |
| TQB | Regence BCBS |
| TQC | BCBS of Minnesota |
| TQD | BCBS of Michigan |
| TQE | Anthem BCBS of Indiana |
| TQF | BCBS of Michigan |
| TQG | Highmark BCBS of Pennsylvania |
| TQH | BCBS of Massachusetts |
| TQI | Wellmark BCBS |
| TQJ | No Prefix Assigned |
| TQK | BCBS of Michigan |
| TQL | Horizon BCBS of New Jersey |
| TQM | BCBS of Minnesota |
| TQN | Anthem BCBS of Colorado |
| TQO | BCBS of North Dakota |
| TQP | Anthem BCBS of Ohio |
| TQQ | BCBS of Minnesota |
| TQR | Regence BCBS |
| TQS | Anthem BCBS of Ohio |
| TQT | Horizon BCBS of New Jersey |
| TQU | BCBS of Minnesota |
| TQV | No Prefix Assigned |
| TQW | Horizon BCBS of New Jersey |
| TQX | No Prefix Assigned |
| TQY | BCBS of Minnesota |
| TQZ | BCBS of Massachusetts |
| TRA | BCBS of Illinois |
| TRB | BCBS of Illinois |
| TRC | BCBS of Illinois |
| TRD | Anthem BCBS of Wisconsin |
| TRE | BCBS of Arizona |
| TRF | BCBS of Michigan |
| TRG | Premera Blue-Cross of Alaska |
| TRH | Anthem BCBS of Virginia |
| TRI | Capital Blue-Cross of Pennsylvania |
| TRJ | Anthem Blue-Cross |
| TRK | BCBS of Illinois |
| TRL | BCBS of Massachusetts |
| TRM | Blue-Shield of California |
| TRN | Anthem BCBS of Connecticut |
| TRO | Carefirst BCBS |
| TRP | BCBS of Minnesota |
| TRQ | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TRR | Wellmark BCBS |
| TRS | BCBS of Kansas City |
| TRT | BCBS of Alabama |
| TRU | Blue-Cross of Idaho |
| TRV | BCBS of Nebraska |
| TRW | BCBS of Illinois |
| TRX | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TRY | BCBS of Minnesota |
| TRZ | Highmark BCBS of Pennsylvania |
| TSA | BCBS of Texas |
| TSB | BCBS of Minnesota |
| TSC | Wellmark BCBS |
| TSD | Wellmark BCBS |
| TSE | Anthem BCBS of Georgia |
| TSF | BCBS of Kansas City |
| TSG | Wellmark BCBS |
| TSH | Blue-Cross of Idaho |
| TSI | BCBS of Illinois |
| TSJ | Anthem BCBS of Connecticut |
| TSK | Anthem BCBS of Virginia |
| TSL | BCBS of Nebraska |
| TSM | Highmark BCBS of Pennsylvania |
| TSN | Anthem BCBS of Georgia |
| TSO | No Prefix Assigned |
| TSP | Wellmark BCBS |
| TSQ | Wellmark BCBS |
| TSR | No Prefix Assigned |
| TSS | No Prefix Assigned |
| TST | Premera BCBS of Alaska |
| TSU | Premera Blue-Cross of Alaska |
| TSV | Wellmark BCBS |
| TSW | Anthem BCBS of Georgia |
| TSX | Anthem BCBS of Ohio |
| TSY | No Prefix Assigned |
| TSZ | No Prefix Assigned |
| TTA | Blue-Cross of Idaho |
| TTB | BCBS of Texas |
| TTC | Anthem BCBS of Ohio |
| TTD | Wellmark BCBS |
| TTE | Wellmark BCBS |
| TTF | BCBS of Texas |
| TTG | Anthem BCBS of Ohio |
| TTH | Carefirst BCBS |
| TTI | No Prefix Assigned |
| TTJ | Florida-Blue |
| TTK | BCBS of Arizona |
| TTL | Anthem BCBS of Indiana |
| TTM | Anthem BCBS of Ohio |
| TTN | Anthem BCBS of Ohio |
| TTO | No Prefix Assigned |
| TTP | Carefirst BCBS |
| TTQ | No Prefix Assigned |
| TTR | BCBS of Michigan |
| TTS | Anthem BCBS of Virginia |
| TTT | No Prefix Assigned |
| TTU | BCBS of Mississippi |
| TTV | Wellmark BCBS |
| TTW | Anthem BCBS of Georgia |
| TTX | BCBS of Massachusetts |
| TTY | Anthem BCBS of Kentucky |
| TTZ | Anthem BCBS of Ohio |
| TUA | Capital Blue-Cross of Pennsylvania |
| TUB | BCBS of Illinois |
| TUC | Anthem BCBS of Ohio |
| TUD | No Prefix Assigned |
| TUE | Highmark BCBS of Pennsylvania |
| TUF | BCBS of Massachusetts |
| TUG | Anthem BCBS of Kentucky |
| TUH | No Prefix Assigned |
| TUI | Regence BCBS |
| TUJ | No Prefix Assigned |
| TUK | BCBS of Illinois |
| TUL | Horizon BCBS of New Jersey |
| TUM | No Prefix Assigned |
| TUN | BCBS of Alabama |
| TUO | BCBS of Tennessee |
| TUP | Anthem BCBS of Wisconsin |
| TUQ | No Prefix Assigned |
| TUR | Empire BCBS of New York |
| TUS | No Prefix Assigned |
| TUT | BCBS of Illinois |
| TUU | Horizon BCBS of New Jersey |
| TUV | Horizon BCBS of New Jersey |
| TUW | No Prefix Assigned |
| TUX | BCBS of Illinois |
| TUY | BCBS of Michigan |
| TUZ | Anthem BCBS of Ohio |
| TVA | BCBS of Tennessee |
| TVB | No Prefix Assigned |
| TVC | BCBS of Massachusetts |
| TVD | No Prefix Assigned |
| TVE | Wellmark BCBS |
| TVF | Regence BCBS |
| TVG | Anthem BCBS of Missouri |
| TVH | No Prefix Assigned |
| TVI | BCBS of Tennessee |
| TVJ | BCBS of Minnesota |
| TVK | Carefirst BCBS |
| TVL | Anthem BCBS of Virginia |
| TVM | Anthem BCBS of Virginia |
| TVN | Anthem BCBS of Georgia |
| TVO | BCBS of Tennessee |
| TVP | No Prefix Assigned |
| TVQ | No Prefix Assigned |
| TVR | No Prefix Assigned |
| TVS | Anthem BCBS of Virginia |
| TVT | BCBS of Minnesota |
| TVU | BCBS of Michigan |
| TVV | Horizon BCBS of New Jersey |
| TVW | Anthem BCBS of Connecticut |
| TVX | No Prefix Assigned |
| TVY | Wellmark BCBS |
| TVZ | Regence BCBS |
| TWA | Anthem BCBS of Georgia |
| TWB | BCBS of Minnesota |
| TWC | BCBS of Illinois |
| TWD | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TWE | BCBS of Massachusetts |
| TWF | Horizon BCBS of New Jersey |
| TWG | BCBS of North Carolina |
| TWH | Blue-Shield of California |
| TWI | Regence BCBS |
| TWJ | Empire BCBS of New York |
| TWK | Anthem BCBS of Ohio |
| TWL | BCBS of Alabama |
| TWM | Empire BCBS of New York |
| TWN | Regence BCBS |
| TWO | Independence Blue-Cross of Philadelphia and Southeastern Pennsylvania |
| TWP | Horizon BCBS of New Jersey |
| TWQ | Empire BCBS of New York |
| TWR | Anthem Blue-Cross |
| TWS | No Prefix Assigned |
| TWT | Carefirst BCBS |
| TWU | Anthem BCBS of Ohio |
| TWV | BCBS of Illinois |
| TWW | Anthem BCBS of Ohio |
| TWX | BCBS of Texas |
| TWY | BCBS of Western New York |
| TWZ | No Prefix Assigned |
| TXA | BCBS of Illinois |
| TXB | No Prefix Assigned |
| TXC | BCBS of Alabama |
| TXD | BCBS of Texas |
| TXE | No Prefix Assigned |
| TXF | No Prefix Assigned |
| TXG | No Prefix Assigned |
| TXH | Anthem BCBS of Maine |
| TXI | No Prefix Assigned |
| TXJ | Anthem BCBS of Nevada |
| TXK | No Prefix Assigned |
| TXL | Anthem BCBS of Wisconsin |
| TXM | Anthem BCBS of Ohio |
| TXN | BCBS of Michigan |
| TXO | No Prefix Assigned |
| TXP | Premera BCBS of Alaska |
| TXQ | No Prefix Assigned |
| TXR | BCBS of Texas |
| TXS | BCBS of Texas |
| TXT | BCBS of Massachusetts |
| TXU | BCBS of Western New York |
| TXV | BCBS of Tennessee |
| TXW | BCBS of Texas |
| TXX | BCBS of Massachusetts |
| TXY | No Prefix Assigned |
| TXZ | BCBS of Tennessee |
| TYA | Premera BCBS of Alaska |
| TYB | Blue-Shield of California |
| TYC | Anthem Blue-Cross |
| TYD | No Prefix Assigned |
| TYE | No Prefix Assigned |
| TYF | Anthem BCBS of Ohio |
| TYG | Arkansas BCBS |
| TYH | No Prefix Assigned |
| TYI | No Prefix Assigned |
| TYJ | No Prefix Assigned |
| TYK | Anthem BCBS of Ohio |
| TYL | BCBS of Texas |
| TYM | Florida-Blue |
| TYN | Horizon BCBS of New Jersey |
| TYO | Blue-Shield of Northeastern New York |
| TYP | Wellmark BCBS |
| TYQ | Carefirst BCBS |
| TYR | Anthem BCBS of Missouri |
| TYS | No Prefix Assigned |
| TYT | BCBS of Illinois |
| TYU | Carefirst BCBS |
| TYV | No Prefix Assigned |
| TYW | BCBS of Arizona |
| TYX | No Prefix Assigned |
| TYY | BCBS of Texas |
| TYZ | Arkansas BCBS |
| TZA | BCBS of Illinois |
| TZB | Highmark BCBS of Pennsylvania |
| TZC | No Prefix Assigned |
| TZD | Anthem BCBS of Ohio |
| TZE | BCBS of Illinois |
| TZF | Horizon BCBS of New Jersey |
| TZG | No Prefix Assigned |
| TZH | No Prefix Assigned |
| TZI | BCBS of Tennessee |
| TZJ | BCBS of Illinois |
| TZK | No Prefix Assigned |
| TZL | Highmark BCBS of Pennsylvania |
| TZM | Anthem Blue-Cross |
| TZN | Anthem BCBS of Ohio |
| TZO | Anthem BCBS of Georgia |
| TZP | No Prefix Assigned |
| TZQ | Anthem BCBS of Ohio |
| TZR | No Prefix Assigned |
| TZS | Premera BCBS of Alaska |
| TZT | Arkansas BCBS |
| TZU | Highmark BCBS of Pennsylvania |
| TZV | Anthem BCBS of Indiana |
| TZW | Highmark BCBS of Pennsylvania |
| TZX | Anthem BCBS of Colorado |
| TZY | Highmark BCBS of Pennsylvania |
| TZZ | No Prefix Assigned |
| T2A | BCBS of Western New York |
| T2B | BCBS of Illinois |
| T2D | BCBS of Texas |
| T2E | BCBS of Texas |
| T2F | BCBS of Texas |
| T2G | BCBS of Texas |
| T2H | BCBS of Illinois |
| T2J | BCBS of Texas |
| T2K | BCBS of Texas |
| T2L | Regence BCBS of Oregon |
| T2M | Anthem Blue Cross of California |
| T2N | Anthem Blue Cross of Virginia |
| T2Q | Blue Cross of California |
| T2R | BCBS of Illinois |
| T2V | Capital Blue Cross |
| T2W | BCBS of Illinois |
| T2X | BCBS of Illinois |
| T2Y | BCBS of North Dakota |
| T2Z | BCBS of Illinois |
| T3A | Regence BCBS of Oregon |
| T3B | Highmark BCBS of Pennsylvania |
| T3C | Regence BCBS of Oregon |
| T3D | Highmark BCBS of Pennsylvania |
| T3H | BCBS of Illinois |
| T3M | Blue Cross of California |
| T3P | BCBS of Minnesota |
| T3R | BCBS of Texas |
| T3T | BCBS of Minnesota |
| T3U | Anthem BCBS of Missouri |
| T4A | Empire BCBS of New York |
| T4B | Empire BCBS of New York |
| T4C | Empire BCBS of New York |
| T4D | Empire BCBS of New York |
| T4E | Empire BCBS of New York |
| T4F | Empire BCBS of New York |
| T4H | BCBS of Illinois |
| T4J | Empire BCBS of New York |
| T4K | Empire BCBS of New York |
| T4L | Empire BCBS of New York |
| T4N | Empire BCBS of New York |
| T4O | Anthem BCBS of Colorado |
| T4P | BCBS of Illinois |
| T4R | BCBS of Texas |
| T4T | BCBS of Massachusetts |
| T4U | Empire BCBS of New York |
| T4V | Empire BCBS of New York |
| T5A | Blue Cross of California |
| T5B | Anthem BCBS of Ohio |
| T5F | Anthem BCBS of Virginia |
| T5G | Anthem BCBS of Indiana |
| T5H | BCBS of Illinois |
| T5N | Anthem BCBS of Georgia |
| T5O | Anthem BCBS of Ohio |
| T5P | Regence BCBS of Oregon |
| T5R | BCBS of Texas |
| T5T | Regence BCBS of Oregon |
| T6A | Empire BCBS of New York |
| T6G | Regence BCBS of Oregon |
| T6H | BCBS of Illinois |
| T7H | BCBS of Illinois |
| T8H | BCBS of Illinois |
| T8R | Premera Blue Cross |
| T8R | Premera Blue Cross |
| T9H | BCBS of Illinois |
