| SAA | Wellmark |
| SAB | Anthem BCBS of Ohio (OH) |
| SAC | Anthem Blue Cross(BC) of California (CA) |
| SAD | BCBS of North Carolina (NC) |
| SAE | Anthem BCBS of Virginia (VA) |
| SAF | Anthem Blue Cross(BC) of California (CA) |
| SAG | Anthem Blue Cross(BC) of California (CA) |
| SAH | BCBS of Illinois (IL) |
| SAI | Anthem BCBS of Ohio (OH) |
| SAJ | Blue Shield (BS) of California (CA) |
| SAK | BCBS of Illinois (IL) |
| SAL | BCBS of South Carolina (SC) / Southcarolinablues |
| SAM | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SAN | Anthem BCBS of Virginia (VA) |
| SAO | Wellmark |
| SAP | Blue Shield (BS) of California |
| SAQ | BCBS of Minnesota (MN) |
| SAR | BCBS Blue Care Network Michigan (MI) |
| SAS | Capital Blue Cross of Pennsylvania (PA) |
| SAT | Wellmark |
| SAU | BCBS of South Carolina (SC) / Southcarolinablues |
| SAV | Unassigned Prefix |
| SAW | Regence BCBS |
| SAX | Empire BCBS of New York (NY) |
| SAY | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SAZ | Unassigned Prefix |
| SBA | Anthem BCBS of Indiana (IN) |
| SBB | Anthem BCBS of Missouri (MO) |
| SBC | BCBS of Illinois (IL) |
| SBD | BCBS of South Carolina (SC) / Southcarolinablues |
| SBE | BCBS of Massachusetts (MA) |
| SBF | BCBS of Illinois (IL) |
| SBG | Unassigned Prefix |
| SBH | Highmark BCBS of Pennsylvania (PA) |
| SBI | Anthem BCBS of Georgia (GA) |
| SBJ | Unassigned Prefix |
| SBK | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SBL | Unassigned Prefix |
| SBM | Unassigned Prefix |
| SBN | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SBO | Unassigned Prefix |
| SBP | BCBS of Texas (TX) |
| SBQ | BCBS of Illinois (IL) |
| SBR BCBS Prefix | Highmark BCBS of Pennsylvania (PA) |
| SBS | Anthem BCBS of Georgia (GA) |
| SBT | Anthem BCBS of Ohio (OH) |
| SBU | Premera BCBS of Alaska (AK) |
| SBV | Anthem Blue Cross(BC) of California (CA) |
| SBW | BCBS of Massachusetts (MA) |
| SBX | BCBS of Massachusetts (MA) |
| SBY | BCBS of Kansas City |
| SBZ | Unassigned Prefix |
| SCA | Regence BCBS |
| SCB | BCBS of South Carolina (SC) / Southcarolinablues |
| SCC | Blue Shield (BS) of California |
| SCD | BCBS of Texas (TX) |
| SCE | BCBS of Illinois (IL) |
| SCF | Anthem BCBS of Virginia (VA) |
| SCG | BCBS of Alabama (AL) |
| SCH | BCBS of Minnesota (MN) |
| SCI | Regence BCBS |
| SCJ | BCBS of Minnesota (MN) |
| SCK | Wellmark |
| SCL | Premera BCBS of Alaska (AK) |
| SCM | BCBS of Texas (TX) |
| SCN | Anthem BCBS of Ohio (OH) |
| SCO | BCBS of Alabama (AL) |
| SCP | Credence BCBS |
| SCQ | Wellmark |
| SCR | BCBS Blue Care Network Michigan (MI) |
| SCS | Capital Blue Cross of Pennsylvania (PA) |
| SCT | Anthem BCBS of Virginia (VA) |
| SCU | Blue Cross (BC) of Idaho (ID) |
| SCV | Horizon BCBS of New Jersey (NJ) |
| SCW | BCBS of Alabama (AL) |
| SCX | BCBS of Illinois (IL) |
| SCY | BCBS of Alabama (AL) |
| SCZ | BCBS of South Carolina (SC) / Southcarolinablues |
| SDA | BCBS of Nebraska (NE) |
| SDB | BCBS of South Carolina (SC) / Southcarolinablues |
| SDC | Anthem BCBS of Virginia (VA) |
| SDD | Blue shield(BS) of Northeastern New York (NeNY) |
| SDE | Highmark BCBS of Delaware (DE) |
| SDF | Wellmark |
| SDG | Anthem Blue Cross(BC) of California (CA) |
| SDH | Wellmark |
| SDI | Unassigned Prefix |
| SDJ | BCBS of Minnesota (MN) |
| SDK | BCBS of South Carolina (SC) / Southcarolinablues |
| SDL | BCBS of South Carolina (SC) / Southcarolinablues |
| SDM | Unassigned Prefix |
| SDN | Anthem BCBS of Connecticut (CT) |
| SDO | BCBS of Illinois (IL) |
| SDP | Empire BCBS of New York (NY) |
| SDQ | Horizon BCBS of New Jersey (NJ) |
| SDR | Highmark BCBS of Pennsylvania (PA) |
| SDS | Excellus BCBS of New York (NY) |
| SDT | BCBS of Alabama (AL) |
| SDU | Anthem Blue Cross(BC) of California (CA) |
| SDV | Anthem BCBS of Ohio (OH) |
| SDW | BCBS of Oklahoma (OK) |
| SDX | BCBS of Minnesota (MN) |
| SDY | Florida (FL) Blue |
| SDZ | Unassigned Prefix |
| SEA | Premera BCBS of Alaska (AK) |
| SEB | BCBS Blue Care Network Michigan (MI) |
| SEC | Florida (FL) Blue |
| SED | BCBS of Illinois (IL) |
| SEE | BCBS Blue Care Network Michigan (MI) |
| SEF | Unassigned Prefix |
| SEG | Anthem BCBS of Kentucky (KY) |
| SHE | BCBS of Alabama (AL) |
| SEI | Highmark BCBS of Pennsylvania (PA) |
| SEJ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SEK | BCBS of South Carolina (SC) / Southcarolinablues |
| SEL | Wellmark |
| SEM | Anthem BCBS of Virginia (VA) |
| SEN | Anthem BCBS of Indiana (IN) |
| SEO | Blue Shield (BS) of California |
| SEP | Capital Blue Cross of Pennsylvania (PA) |
| SEQ | Unassigned Prefix |
| SER | Anthem BCBS of Virginia (VA) |
| SES | BCBS Blue Care Network Michigan (MI) |
| SET | BCBS of Texas (TX) |
| SEU | Wellmark |
| SEV | BCBS of North Carolina (NC) |
| SEW | BCBS of Tennessee (TN) |
| SEX | Unassigned Prefix |
| SEY | Anthem Blue Cross(BC) of California (CA) |
| SEZ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SFA | Empire BCBS of New York (NY) |
| SFB | BCBS of Illinois (IL) |
| SFC | Wellmark |
| SFD | Unassigned Prefix |
| SFE | Unassigned Prefix |
| SFF | BCBS of Tennessee (TN) |
| SFG | Blue Shield (BS) of California |
| SFH | Wellmark |
| SFI | BCBS of Illinois (IL) |
| SFJ | Wellmark |
| SFK | Anthem BCBS of Ohio (OH) |
| SFL | Florida (FL) Blue |
| SFM | BCBS of Alabama (AL) |
| SFN | Wellmark |
| SFO | BCBS of Massachusetts (MA) |
| SFP | BCBS of Illinois (IL) |
| SFQ | BCBS of Mississippi (MS) |
| SFR | BCBS of South Carolina (SC) / Southcarolinablues |
| SFS | BCBS of Tennessee (TN) |
| SFT | Arkansas (AR) Blue Cross |
| SFU | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SFV | Anthem BCBS of Virginia (VA) |
| SFW | Empire BCBS of New York (NY) |
| SFX | Anthem BCBS of Missouri (MO) |
| SFY | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SFZ BCBS Prefix | BCBS of Illinois (IL) |
| SGA | BCBS of South Carolina (SC) / Southcarolinablues |
| SGB | BCBS Blue Care Network Michigan (MI) |
| SGC | BCBS Blue Care Network Michigan (MI) |
| SGD | Unassigned Prefix |
| SGE | Anthem Blue Cross(BC) of California (CA) |
| SGF | Anthem BCBS of Kentucky (KY) |
| SGG | BCBS of Illinois (IL) |
| SGH | Horizon BCBS of New Jersey (NJ) |
| SGI | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SGJ | Blue Cross (BC) of Idaho (ID) |
| SGK | Unassigned Prefix |
| SGL | Regence BCBS |
| SGM | BCBS Blue Care Network Michigan (MI) |
| SGN | BCBS of Louisiana(LA) |
| SGO | BCBS of Massachusetts (MA) |
| SGP | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SGQ | Unassigned Prefix |
| SGR | BCBS of Massachusetts (MA) |
| SGS | BCBS of South Carolina (SC) / Southcarolinablues |
| SGT | BCBS of Massachusetts (MA) |
| SGU | Florida (FL) Blue |
| SGV | Anthem Blue Cross(BC) of California (CA) |
| SGW | BCBS of Illinois (IL) |
| SGX | Horizon BCBS of New Jersey (NJ) |
| SGY | Anthem BCBS of Ohio (OH) |
| SGZ | Horizon BCBS of New Jersey (NJ) |
| SHA | Anthem BCBS of Missouri (MO) |
| SHB | Anthem BCBS of Ohio (OH) |
| SHC | Anthem Blue Cross(BC) of California (CA) |
| SHD | Empire BCBS of New York (NY) |
| SHE | Wellmark |
| SHF | Anthem BCBS of Missouri (MO) |
| SHG | Capital Blue Cross of Pennsylvania (PA) |
| SHH | BCBS of Kansas City |
| SHI | Wellmark |
| SHJ | Unassigned Prefix |
| SHK | BCBS of Alabama (AL) |
| SHL | Anthem BCBS of Georgia (GA) |
| SHM | Empire BCBS of New York (NY) |
| SHN | BCBS of Illinois (IL) |
| SHO | Anthem Blue Cross(BC) of California (CA) |
| SHP BCBS Prefix | Anthem BCBS of Connecticut (CT) |
| SHQ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SHR | BCBS of Massachusetts (MA) |
| SHS | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SHT | BCBS of Texas (TX) |
| SHU | Unassigned Prefix |
| SHV | Unassigned Prefix |
| SHW | Anthem BCBS of Virginia (VA) |
| SHX | BCBS of Louisiana(LA) |
| SHY | Unassigned Prefix |
| SHZ | BCBS of North Dakota (ND) |
| SIA | Wellmark |
| SIB | BCBS of South Carolina (SC) / Southcarolinablues |
| SIC | Blue Shield (BS) of California |
| SID | Regence BCBS |
| SIE | Unassigned Prefix |
| SIF | Anthem Blue Cross(BC) of California (CA) |
| SIG | BCBS of Massachusetts (MA) |
| SIH | Empire BCBS of New York (NY) |
| SII | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SIJ | Anthem BCBS of Georgia (GA) |
| SIK | Unassigned Prefix |
| SIL | Blue Shield (BS) of California |
| SIM | Arkansas (AR) Blue Cross |
| SIN | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SIO | BCBS of North Carolina (NC) |
| SIP | Unassigned Prefix |
| SIQ | Unassigned Prefix |
| SIR | Anthem Blue Cross(BC) of California (CA) |
| SIS | Unassigned Prefix |
| SIT | Anthem BCBS of Ohio (OH) |
| SIU | BCBS of Illinois (IL) |
| SIV | Blue Shield (BS) of California |
| SIW | BCBS of Illinois (IL) |
| SIX | Unassigned Prefix |
| SIY | Anthem BCBS of Ohio (OH) |
| SIZ | Wellmark |
| SJA | Anthem BCBS of Ohio (OH) |
| SJB | Anthem BCBS of Ohio (OH) |
| SJC | Florida (FL) Blue |
| SJD | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SJE | Anthem BCBS of Ohio (OH) |
| SJF | Anthem BCBS of Ohio (OH) |
| SJG | Anthem BCBS of Connecticut (CT) |
| SJH | Anthem BCBS of Ohio (OH) |
| SJI | BCBS of Louisiana(LA) |
| SJJ | Unassigned Prefix |
| SJK | Arkansas (AR) Blue Cross |
| SJL | BCBS of Illinois (IL) |
| SJM | Unassigned Prefix |
| SJN | Anthem BCBS of Georgia (GA) |
| SJO | Anthem Blue Cross(BC) of California (CA) |
| SJP | BCBS of Illinois (IL) |
| SJQ | Unassigned Prefix |
| SJR | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SJS | BCBS of South Carolina (SC) / Southcarolinablues |
| SJT | BCBS of Alabama (AL) |
| SJU | BCBS of Massachusetts (MA) |
| SJV | Unassigned Prefix |
| SJW | Unassigned Prefix |
| SJX | BCBS of South Carolina (SC) / Southcarolinablues |
| SJY | Blue Shield (BS) of California |
| SJZ | Highmark BCBS of Pennsylvania (PA) |
| SKA | BCBS of Minnesota (MN) |
| SKB | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SKC | Unassigned Prefix |
| SKD | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SKE | Unassigned Prefix |
| SKF | Anthem BCBS of Wisconsin (WI) |
| SKG | Anthem BCBS of Georgia (GA) |
| SKH | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SKI | Anthem BCBS of Georgia (GA) |
| SKJ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SKK | BCBS of Illinois (IL) |
| SKL | BCBS of Illinois (IL) |
| SKM | Unassigned Prefix |
| SKN | BCBS of Texas (TX) |
| SKO | Premera BCBS of Alaska (AK) |
| SKP | BCBS of Minnesota (MN) |
| SKQ | Anthem BCBS of Ohio (OH) |
| SKR | Unassigned Prefix |
| SKS | BCBS of Illinois (IL) |
| SKT | BCBS of Nebraska (NE) |
| SKU | BCBS of North Carolina (NC) |
| SKV | Unassigned Prefix |
| SKW | Anthem BCBS of Georgia (GA) |
| SKX | BCBS of Texas (TX) |
| SKY | BCBS of Illinois (IL) |
| SKZ | Unassigned Prefix |
| SLA | BCBS of South Carolina (SC) / Southcarolinablues |
| SLB | BCBS of Kansas City |
| SLC | BCBS of Louisiana(LA) |
| SLD | Unassigned Prefix |
| SLE | Anthem BCBS of Colorado (CO) |
| SLF | Highmark BCBS of Pennsylvania (PA) |
| SLG | Anthem Blue Cross(BC) of California (CA) |
| SLH | Premera BCBS of Alaska (AK) |
| SLI | BCBS of Alabama (AL) |
| SLJ | Unassigned Prefix |
| SLK | BCBS of Minnesota (MN) |
| SLL | Highmark BCBS of Delaware (DE) |
| SLM | BCBS of Louisiana(LA) |
| SLN | BCBS of Minnesota (MN) |
| SLO | Unassigned Prefix |
| SLP | Unassigned Prefix |
| SLQ | Unassigned Prefix |
| SLR | BCBS of Texas (TX) |
| SLS | Florida (FL) Blue |
| SLT | BCBS of Massachusetts (MA) |
| SLU | Capital Blue Cross of Pennsylvania (PA) |
| SLV | Unassigned Prefix |
| SLW | BCBS of Western New York (WNY) |
| SLX | Capital Blue Cross of Pennsylvania (PA) |
| SLY | Unassigned Prefix |
| SLZ | Unassigned Prefix |
| SMA | BCBS of Nebraska (NE) |
| SMB | Anthem BCBS of Ohio (OH) |
| SMC | BCBS of Minnesota (MN) |
| SMD | Anthem BCBS of Indiana (IN) |
| SME | Empire BCBS of New York (NY) |
| SMF | Anthem BCBS of Virginia (VA) |
| SMG | Wellmark |
| SMH | BCBS of Alabama (AL) |
| SMI | Unassigned Prefix |
| SMJ | Horizon BCBS of New Jersey (NJ) |
| SMK | BCBS Blue Care Network Michigan (MI) |
| SML | BCBS of Illinois (IL) |
| SMM | Anthem BCBS of Ohio (OH) |
| SMN | Empire BCBS of New York (NY) |
| SMO | Unassigned Prefix |
| SMP | Anthem BCBS of Ohio (OH) |
| SMQ | Unassigned Prefix |
| SMR | Unassigned Prefix |
| SMS | Wellmark |
| SMT | Anthem BCBS of Virginia (VA) |
| SMU | BCBS Blue Care Network Michigan (MI) |
| SMV | BCBS Blue Care Network Michigan (MI) |
| SMW | BCBS of Illinois (IL) |
| SMX | BCBS Blue Care Network Michigan (MI) |
| SMY | BCBS of Alabama (AL) |
| SMZ | BCBS of South Carolina (SC) / Southcarolinablues |
| SNA | Anthem Blue Cross(BC) of California (CA) |
| SNB | BCBS of Texas (TX) |
| SNC | Unassigned Prefix |
| SND | Unassigned Prefix |
| SNE | BCBS of Minnesota (MN) |
| SNF | Unassigned Prefix |
| SNG | Unassigned Prefix |
| SNH | Unassigned Prefix |
| SNI | Unassigned Prefix |
| SNJ | Horizon BCBS of New Jersey (NJ) |
| SNK | BCBS of Arizona (AZ) |
| SNL | BCBS of Illinois (IL) |
| SNM | Unassigned Prefix |
| SNN | Unassigned Prefix |
| SNO | BCBS of South Carolina (SC) / Southcarolinablues |
| SNP | BCBS of Minnesota (MN) |
| SNQ | BCBS of Rhode Island (RI) |
| SNR | Unassigned Prefix |
| SNS | BCBS of Illinois (IL) |
| SNT | Unassigned Prefix |
| SNU | Anthem BCBS of Missouri (MO) |
| SNV | BCBS Blue Care Network Michigan (MI) |
| SNW | Unassigned Prefix |
| SNX | Anthem Blue Cross(BC) of California (CA) |
| SNY | Credence BCBS |
| SNZ | BCBS of Minnesota (MN) |
| SOA | Regence BCBS |
| SOB | BCBS Blue Care Network Michigan (MI) |
| SOC | Blue Shield (BS) of California |
| SOD | Highmark BCBS of Delaware (DE) |
| SOE | BCBS of Illinois (IL) |
| SOF | Anthem BCBS of Ohio (OH) |
| SOG | Unassigned Prefix |
| SOH | Unassigned Prefix |
| SOI | Unassigned Prefix |
| SOJ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SOK | Blue Shield (BS) of California |
| SOL | BCBS of North Carolina (NC) |
| SOM | Unassigned Prefix |
| SON | Blue Shield (BS) of California |
| SOO | Blue Shield (BS) of California |
| SOP | BCBS of Massachusetts (MA) |
| SOQ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SOR | Anthem BCBS of Kentucky (KY) |
| SOS | Florida (FL) Blue |
| SOT | Unassigned Prefix |
| SOU | Anthem BCBS of Missouri (MO) |
| SOV | Unassigned Prefix |
| SOW | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SOX | BCBS of Nebraska (NE) |
| SOY | Unassigned Prefix |
| SOZ | Unassigned Prefix |
| SPA | Anthem BCBS of Georgia (GA) |
| SPB | BCBS of Tennessee (TN) |
| SPC | Unassigned Prefix |
| SPD | Anthem BCBS of Ohio (OH) |
| SPE | BCBS of Kansas City |
| SPF | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SPG | Blue Shield (BS) of California |
| SPH | BCBS of Arizona (AZ) |
| SPI | Anthem Blue Cross(BC) of California (CA) |
| SPJ | BCBS of South Carolina (SC) / Southcarolinablues |
| SPK | Anthem BCBS of Virginia (VA) |
| SPL | BCBS of Illinois (IL) |
| SPM | Unassigned Prefix |
| SPN | BCBS of Texas (TX) |
| SPO | BCBS of Western New York (WNY) |
| SPP | Unassigned Prefix |
| SPQ | BCBS of Illinois (IL) |
| SPR | Anthem BCBS of Virginia (VA) |
| SPS | BCBS of Massachusetts (MA) |
| SPT | BCBS of Minnesota (MN) |
| SPU | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SPV | Unassigned Prefix |
| SPW | Blue Shield (BS) of California |
| SPX | Blue Cross (BC) of Idaho (ID) |
| SPY | Unassigned Prefix |
| SPZ | Unassigned Prefix |
| SQA | Unassigned Prefix |
| SQB | Unassigned Prefix |
| SQC | Anthem BCBS of Ohio (OH) |
| SQD | Anthem BCBS of Georgia (GA) |
| SQE | BCBS of Minnesota (MN) |
| SQF | Unassigned Prefix |
| SQG | Anthem BCBS of Ohio (OH) |
| SQH | Anthem BCBS of Indiana (IN) |
| SQI | Unassigned Prefix |
| SQJ | Anthem BCBS of Colorado (CO) |
| SQK | Anthem Blue Cross(BC) of California (CA) |
| SQL | Unassigned Prefix |
| SQM | Blue Shield (BS) of California |
| SQN | Premera BCBS of Alaska (AK) |
| SQO | BCBS Blue Care Network Michigan (MI) |
| SQP | Regence BCBS |
| SQQ | Blue Cross (BC) of Idaho (ID) |
| SQR | BCBS of Minnesota (MN) |
| SQS | Anthem BCBS of Georgia (GA) |
| SQT | Anthem BCBS of Virginia (VA) |
| SQU | BCBS of South Carolina (SC) / Southcarolinablues |
| SQV | Anthem BCBS of Georgia (GA) |
| SQW | Horizon BCBS of New Jersey (NJ) |
| SQX | Anthem BCBS of Ohio (OH) |
| SQY | BCBS of South Carolina (SC) / Southcarolinablues |
| SQZ | Anthem BCBS of Ohio (OH) |
| SRA | Horizon BCBS of New Jersey (NJ) |
| SRB | Anthem BCBS of Missouri (MO) |
| SRC | BCBS of South Carolina (SC) / Southcarolinablues |
| SRD | Horizon BCBS of New Jersey (NJ) |
| SRE | BCBS of Louisiana(LA) |
| SRF | BCBS of North Carolina (NC) |
| SRG | Blue Shield (BS) of California |
| SRH | Capital Blue Cross of Pennsylvania (PA) |
| SRI | Highmark BCBS of Pennsylvania (PA) |
| SRJ | Regence BCBS |
| SRK | Anthem BCBS of Ohio (OH) |
| SRL | BCBS of Western New York (WNY) |
| SRM | Anthem BCBS of Missouri (MO) |
| SRN | Anthem BCBS of Georgia (GA) |
| SRO | Excellus BCBS of New York (NY) |
| SRP | BCBS of South Carolina (SC) / Southcarolinablues |
| SRQ | Anthem Blue Cross(BC) of California (CA) |
| SRR | Anthem BCBS of Georgia (GA) |
| SRS | BCBS of South Carolina (SC) / Southcarolinablues |
| SRT | Anthem BCBS of Wisconsin (WI) |
| SRU | Premera BCBS of Alaska (AK) |
| SRV | Anthem BCBS of Missouri (MO) |
| SRW | BCBS of Massachusetts (MA) |
| SRX | Anthem BCBS of Georgia (GA) |
| SRY | BCBS of Illinois (IL) |
| SRZ | Anthem BCBS of Missouri (MO) |
| SSA | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SSB | Unassigned Prefix |
| SSC | BCBS of North Carolina (NC) |
| SSD | Blue Shield (BS) of California |
| SSE | BCBS of Minnesota (MN) |
| SSF | Anthem BCBS of Missouri (MO) |
| SSG | Wellmark |
| SSH | Unassigned Prefix |
| SSI | BCBS of Minnesota (MN) |
| SSJ | Unassigned Prefix |
| SSK | Empire BCBS of New York (NY) |
| SSL | Blue Shield (BS) of California |
| SSM | Anthem BCBS of Georgia (GA) |
| SSN | Unassigned Prefix |
| SSO | Blue Shield (BS) of California |
| SSP | Unassigned Prefix |
| SSQ | Blue Cross (BC) of Idaho (ID) |
| SSR | Unassigned Prefix |
| SSS | Regence BCBS |
| SST | BCBS of Massachusetts (MA) |
| SSU | Anthem Blue Cross(BC) of California (CA) |
| SSV | Unassigned Prefix |
| SSW | Unassigned Prefix |
| SSX | BCBS of Texas (TX) |
| SSY | Anthem Blue Cross(BC) of California (CA) |
| SSZ | Premera BCBS of Alaska (AK) |
| STA | BCBS of Tennessee (TN) |
| STB | Anthem BCBS of Ohio (OH) |
| STC | BCBS of Alabama (AL) |
| STD | Capital Blue Cross of Pennsylvania (PA) |
| STE | Wellmark |
| STF | Anthem BCBS of Indiana (IN) |
| STG | BCBS of Tennessee (TN) |
| STH | Anthem BCBS of Georgia (GA) |
| STI | BCBS of Texas (TX) |
| STJ | Premera Blue Cross (BC) of Alaska (AK) |
| STK | BCBS of South Carolina (SC) / Southcarolinablues |
| STL | BCBS of Tennessee (TN) |
| STM | Highmark BCBS of Pennsylvania (PA) |
| STN | Highmark BCBS of Pennsylvania (PA) |
| STO | Unassigned Prefix |
| STP | BCBS of Texas (TX) |
| STQ | BCBS of Tennessee (TN) |
| STR | Anthem BCBS of Indiana (IN) |
| STS | Blue Shield (BS) of California |
| STT | BCBS of Tennessee (TN) |
| STU | Wellmark |
| STV | BCBS of Tennessee (TN) |
| STW | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| STX | BCBS of Illinois (IL) |
| STY | Anthem BCBS of Indiana (IN) |
| STZ | Florida (FL) Blue |
| SUA | BCBS of Minnesota (MN) |
| SUB | Horizon BCBS of New Jersey (NJ) |
| SUC | Horizon BCBS of New Jersey (NJ) |
| SUD | Excellus BCBS of New York (NY) |
| SUE | Capital Blue Cross of Pennsylvania (PA) |
| SUF | Empire BCBS of New York (NY) |
| SUG | BCBS of Massachusetts (MA) |
| SUH | BCBS of North Carolina (NC) |
| SUI | Anthem BCBS of Ohio (OH) |
| SUJ | Anthem BCBS of Georgia (GA) |
| SUK | Unassigned Prefix |
| SUL | Wellmark |
| SUM | BCBS of Alabama (AL) |
| SUN | BCBS of Illinois (IL) |
| SUO | Unassigned Prefix |
| SUP | BCBS of Illinois (IL) |
| SUQ | Unassigned Prefix |
| SUR | BCBS of Illinois (IL) |
| SUS | Excellus BCBS of New York (NY) |
| SUT | Anthem Blue Cross(BC) of California (CA) |
| SUU | BCBS of South Carolina (SC) / Southcarolinablues |
| SUV | BCBS of Alabama (AL) |
| SUW | BCBS of Western New York (WNY) |
| SUX | Horizon BCBS of New Jersey (NJ) |
| SUY | Horizon BCBS of New Jersey (NJ) |
| SUZ | Horizon BCBS of New Jersey (NJ) |
| SVA | Unassigned Prefix |
| SVB | BCBS Blue Care Network Michigan (MI) |
| SVC | Premera BCBS of Alaska (AK) |
| SVD | BCBS of Kansas City |
| SVE | BCBS of Tennessee (TN) |
| SVF | Capital Blue Cross of Pennsylvania (PA) |
| SVG | BCBS of Kansas City |
| SVH | BCBS of Minnesota (MN) |
| SVI | Unassigned Prefix |
| SVJ | Unassigned Prefix |
| SVK | BCBS of Mississippi (MS) |
| SVL | BCBS of Kansas |
| SVM | Unassigned Prefix |
| SVN | BCBS of North Carolina (NC) |
| SVO | Blue Shield (BS) of California |
| SVP | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SVQ | BCBS of Oklahoma (OK) |
| SVR | Anthem BCBS of Georgia (GA) |
| SVS | Anthem BCBS of Georgia (GA) |
| SVT | BCBS of Minnesota (MN) |
| SVU | BCBS of Illinois (IL) |
| SVV | Unassigned Prefix |
| SVW | Unassigned Prefix |
| SVX | Blue Shield (BS) of California |
| SVY | BCBS of Minnesota (MN) |
| SVZ | Unassigned Prefix |
| SWA | Unassigned Prefix |
| SWB | BCBS of Arizona (AZ) |
| SWC | Unassigned Prefix |
| SWD | BCBS of Massachusetts (MA) |
| SWE | Unassigned Prefix |
| SWF | Unassigned Prefix |
| SWG | Anthem BCBS of Ohio (OH) |
| SWH | BCBS of Illinois (IL) |
| SWI | Anthem BCBS of Georgia (GA) |
| SWJ | BCBS of Illinois (IL) |
| SWK | BCBS of Illinois (IL) |
| SWL | Unassigned Prefix |
| SWM | Unassigned Prefix |
| SWN | Unassigned Prefix |
| SWO | Unassigned Prefix |
| SWP | Anthem BCBS of Kentucky (KY) |
| SWQ | Unassigned Prefix |
| SWR | Highmark BCBS of Pennsylvania (PA) |
| SWS | BCBS of Massachusetts (MA) |
| SWT | BCBS of Arizona (AZ) |
| SWU | Anthem BCBS of Ohio (OH) |
| SWV | Anthem BCBS of Wisconsin (WI) |
| SWW | Wellmark |
| SWX | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SWY | BCBS of Minnesota (MN) |
| SWZ | Highmark BCBS of Pennsylvania (PA) |
| SXA | Arkansas (AR) Blue Cross |
| SXB | Wellmark |
| SXC | Anthem BCBS of Ohio (OH) |
| SXD | Blue Shield (BS) of California |
| SXE | Anthem BCBS of Ohio (OH) |
| SXF | Unassigned Prefix |
| SXG | Unassigned Prefix |
| SXH | Unassigned Prefix |
| SXI | Anthem BCBS of Ohio (OH) |
| SXJ | Anthem Blue Cross(BC) of California (CA) |
| SXK | Empire BCBS of New York (NY) |
| SXL | Unassigned Prefix |
| SXM | Blue Shield (BS) of California |
| SXN | Regence BCBS |
| SXO | BCBS Blue Care Network Michigan (MI) |
| SXP | Unassigned Prefix |
| SXQ | Anthem BCBS of Ohio (OH) |
| SXR | Unassigned Prefix |
| SXS | Unassigned Prefix |
| SXT | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SXU | Unassigned Prefix |
| SXV | Blue Cross (BC) of Idaho (ID) |
| SXW | BCBS of Illinois (IL) |
| SXX | BCBS of Illinois (IL) |
| SXY | BCBS of Massachusetts (MA) |
| SXZ | Anthem Blue Cross(BC) of California (CA) |
| SYA | Anthem BCBS of Ohio (OH) |
| SYB | BCBS of Illinois (IL) |
| SYC | Anthem BCBS of Ohio (OH) |
| SYD | BCBS of Arizona (AZ) |
| SYE | BCBS of South Carolina (SC) / Southcarolinablues |
| SYF | BCBS of Alabama (AL) |
| SYG | BCBS of Minnesota (MN) |
| SYH | BCBS of Minnesota (MN) |
| SYI | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SYJ | Wellmark |
| SYK | Regence BCBS |
| SYL | Unassigned Prefix |
| SYM | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SYN | Unassigned Prefix |
| SYO | BCBS Blue Care Network Michigan (MI) |
| SYP | Anthem BCBS of Georgia (GA) |
| SYQ | BCBS Blue Care Network Michigan (MI) |
| SYR | Highmark BCBS of Pennsylvania (PA) |
| SYS | Anthem BCBS of Wisconsin (WI) |
| SYT | BCBS of Tennessee (TN) |
| SYU | BCBS of Massachusetts (MA) |
| SYV | Unassigned Prefix |
| SYW | Unassigned Prefix |
| SYX | BCBS of Alabama (AL) |
| SYY BCBS Prefix | BCBS of Illinois (IL) |
| SYZ | Premera BCBS of Alaska (AK) |
| SZA | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
| SZB | Regence BCBS |
| SZC | BCBS of Illinois (IL) |
| SZD | BCBS of Massachusetts (MA) |
| SZE | BCBS of Illinois (IL) |
| SZF | BCBS of Illinois (IL) |
| SZG | Unassigned Prefix |
| SZH | Anthem BCBS of Virginia (VA) |
| SZI | Anthem BCBS of Georgia (GA) |
| SZJ | Highmark BCBS of Delaware (DE) |
| SZK | Wellmark |
| SZL | Carefirst BCBS of Maryland (MD)/ District of Columbia (DC) and Northern Virginia (VA) |
| SZM | Highmark BCBS of Pennsylvania (PA) |
| SZN | BCBS of Nebraska (NE) |
| SZO | Blue shield(BS) of Northeastern New York (NeNY) |
| SZP | Unassigned Prefix |
| SZQ | Anthem BCBS of Ohio (OH) |
| SZR | Premera BCBS of Alaska (AK) |
| SZS | Anthem BCBS of Ohio (OH) |
| SZT | Unassigned Prefix |
| SZU | Anthem BCBS of Ohio (OH) |
| SZV | Unassigned Prefix |
| SZW | Unassigned Prefix |
| SZX | Premera BCBS of Alaska (AK) |
| SZY BCBS Prefix | Anthem Blue Cross(BC) of California (CA) |
| SZZ | Independence Blue Cross(BC) of Philadelphia(Phi) and Southeastern Pennsylvania(PA) |
