| Prefix Plan Name |
| O2A Blue Cross of California |
| O2E Blue Cross of California |
| O2N Highmark BCBS of Pennsylvania |
| O2T Blue Cross Blue Shield of Minnesota |
| O3T Regence Blue Cross Blue Shield of Oregon |
| O3V Premera Blue Cross |
| OAA Blue Cross Blue Shield of Massachusetts |
| OAB Blue Cross Blue Shield of Massachusetts |
| OAC Anthem BCBS of Ohio |
| OAD BCBS of Western New York |
| OAE Anthem BCBS of Ohio |
| OAF Anthem BCBS of Virginia |
| OAG Anthem BCBS of Colorado |
| OAH Empire Blue Cross Blue Shield |
| OAI Blue Shield of California |
| OAJ Unassigned |
| OAK Independence Blue Cross |
| OAL Blue Shield of California |
| OAM Highmark BCBS of Pennsylvania |
| OAN Unassigned |
| OAO Unassigned |
| OAP Anthem BCBS of Kentucky |
| OAQ CareFirst BCBS |
| OAR CareFirst BCBS |
| OAS Anthem BCBS of Ohio |
| OAT Blue Cross Blue Shield of Nebraska |
| OAU Blue Cross Blue Shield of Michigan |
| OAV Unassigned |
| OAW Unassigned |
| OAX CareFirst BCBS |
| OAY CareFirst BCBS |
| OAZ Blue Cross Blue Shield of Massachusetts |
| OBA Blue Cross of California |
| OBB Highmark BCBS |
| OBC Blue Cross Blue Shield of Massachusetts |
| OBD Blue Cross Blue Shield of South Carolina |
| OBE Blue Cross Blue Shield of Michigan |
| OBF Highmark BCBS of Pennsylvania |
| OBG BCBS of Tennessee |
| OBH CareFirst BCBS |
| OBI Blue Cross Blue Shield of Minnesota |
| OBJ Premera Blue Cross |
| OBK Unassigned |
| OBL CareFirst BCBS |
| OBM CareFirst BCBS |
| OBN Blue Cross Blue Shield of Massachusetts |
| OBO Highmark BCBS of Pennsylvania |
| OBP Blue Shield of California |
| OBQ Blue Cross of California |
| OBR Wellmark BCBS |
| OBS Blue Cross of Idaho |
| OBT Blue Cross Blue Shield of Arizona |
| OBU Blue Cross Blue Shield of Alabama |
| OBV Blue Cross of California |
| OBW Independence Blue Cross |
| OBX Blue Cross of California |
| OBY CareFirst BCBS |
| OBZ Blue Shield of California |
| OCA Blue Cross of California |
| OCB Anthem BCBS of Virginia |
| OCC Blue Cross of California |
| OCD Blue Shield of California |
| OCE Unassigned |
| OCF Anthem BCBS of Virginia |
| OCG Wellmark BCBS |
| OCH BCBS of Western New York |
| OCI Anthem BCBS of Wisconsin |
| OCJ Blue Shield of California |
| OCK Blue Cross Blue Shield of South Carolina |
| OCL CareFirst BCBS |
| OCM Wellmark BCBS |
| OCN Regence Blue Cross Blue Shield of Oregon |
| OCO Blue Shield of California |
| OCP Anthem BCBS of Ohio |
| OCQ Independence Blue Cross |
| OCR Independence Blue Cross |
| OCS BCBS of Florida |
| OCT Blue Cross of Idaho |
| OCU Anthem BCBS of Ohio |
| OCV CareFirst BCBS |
| OCW Blue Cross of California |
| OCX CareFirst BCBS |
| OCY CareFirst BCBS |
| OCZ Independence Blue Cross |
| ODA CareFirst BCBS |
| ODB Anthem BCBS of Ohio |
| ODC Wellmark BCBS |
| ODD Blue Cross Blue Shield of Nebraska |
| ODE Blue Cross of Idaho |
| ODF Blue Cross Blue Shield of Massachusetts |
| ODG Unassigned |
| ODH Blue Shield of California |
| ODI BCBS of Western New York |
| ODJ BCBS of Tennessee |
| ODK CareFirst BCBS |
| ODL BCBS of Tennessee |
| ODM Blue Cross Blue Shield of Arizona |
| ODN BCBS of Tennessee |
| ODO CareFirst BCBS |
| ODP Unassigned |
