| Z2A | - | Prefix Unallocated/Not Assigned |
| Z2B | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z2C | - | Prefix Unallocated/Not Assigned |
| Z2D | - | Prefix Unallocated/Not Assigned |
| Z2E | - | Prefix Unallocated/Not Assigned |
| Z2F | Minnesota | Blue-Cross Blue-Shield of Minnesota |
| Z2G | - | Prefix Unallocated/Not Assigned |
| Z2H | South Dakota/Iowa | Wellmark Blue-Cross Blue-Shield |
| Z2I | - | Prefix Unallocated/Not Assigned |
| Z2J | - | Prefix Unallocated/Not Assigned |
| Z2K | Alabama | Blue-Cross Blue-Shield of Alabama |
| Z2L | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| Z2M | Rhode Island | Blue-Cross Blue-Shield of Rhode Island |
| Z2N | - | Prefix Unallocated/Not Assigned |
| Z2O | - | Prefix Unallocated/Not Assigned |
| Z2P | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| Z2Q | - | Prefix Unallocated/Not Assigned |
| Z2R | - | Prefix Unallocated/Not Assigned |
| Z2S | South Dakota/Iowa | Wellmark Blue-Cross Blue-Shield |
| Z2T | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z2U | - | Prefix Unallocated/Not Assigned |
| Z2V | - | Prefix Unallocated/Not Assigned |
| Z2W | - | Prefix Unallocated/Not Assigned |
| Z2X | - | Prefix Unallocated/Not Assigned |
| Z2Y | - | Prefix Unallocated/Not Assigned |
| Z2Z | - | Prefix Unallocated/Not Assigned |
| Z3A | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z3B | Connecticut | Anthem Blue-Cross Blue-Shield of Connecticut |
| Z3C | - | Prefix Unallocated/Not Assigned |
| Z3D | - | Prefix Unallocated/Not Assigned |
| Z3E | - | Prefix Unallocated/Not Assigned |
| Z3F | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z3G | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z3H | South Dakota/Iowa | Wellmark Blue-Cross Blue-Shield |
| Z3I | - | Prefix Unallocated/Not Assigned |
| Z3J | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z3K | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z3L | New Hampshire | Anthem Blue-Cross Blue-Shield of New Hampshire |
| Z3M | Rhode Island | Blue-Cross Blue-Shield of Rhode Island |
| Z3N | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z3O | - | Prefix Unallocated/Not Assigned |
| Z3P | - | Prefix Unallocated/Not Assigned |
| Z3Q | - | Prefix Unallocated/Not Assigned |
| Z3R | Massachusetts | Blue-Cross Blue-Shield of Massachusetts |
| Z3S | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z3T | - | Prefix Unallocated/Not Assigned |
| Z3U | - | Prefix Unallocated/Not Assigned |
| Z3V | - | Prefix Unallocated/Not Assigned |
| Z3W | - | Prefix Unallocated/Not Assigned |
| Z3X | New Hampshire | Anthem Blue-Cross Blue-Shield of New Hampshire |
| Z3Y | - | Prefix Unallocated/Not Assigned |
| Z3Z | - | Prefix Unallocated/Not Assigned |
| Z4A | - | Prefix Unallocated/Not Assigned |
| Z4B | Colorado | Anthem Blue-Cross Blue-Shield of Colorado |
| Z4C | - | Couple Health |
| Z4D | - | Prefix Unallocated/Not Assigned |
| Z4E | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z4F | - | Prefix Unallocated/Not Assigned |
| Z4G | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z4H | - | Prefix Unallocated/Not Assigned |
| Z4I | - | Prefix Unallocated/Not Assigned |
| Z4J | - | Prefix Unallocated/Not Assigned |
| Z4K | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z4L | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z4M | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z4N | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z4O | - | Prefix Unallocated/Not Assigned |
| Z4P | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z4Q | - | Prefix Unallocated/Not Assigned |
| Z4R | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z4S | - | Prefix Unallocated/Not Assigned |
| Z4T | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z4U | - | Prefix Unallocated/Not Assigned |
| Z4V | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z4W | - | Prefix Unallocated/Not Assigned |
| Z4X | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z4Y | - | Prefix Unallocated/Not Assigned |
| Z4Z | California | Anthem Blue-Cross |
| Z5A | Illinois | Blue-Cross Blue-Shield of Illinois |
| Z5B | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5C | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5D | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5E | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5F | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5G | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5H | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5I | - | Prefix Unallocated/Not Assigned |
| Z5J | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5K | New York (Northeastern) | Blue-Shield of Northeastern New York |
| Z5L | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5M | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z5N | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5O | - | Prefix Unallocated/Not Assigned |
| Z5P | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5Q | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5R | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5S | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5T | - | Prefix Unallocated/Not Assigned |
| Z5U | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5V | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5W | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5X | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z5Y | - | Prefix Unallocated/Not Assigned |
| Z5Z | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z6A | New York | Empire Blue-Cross Blue-Shield of New York |
| Z6B | - | Prefix Unallocated/Not Assigned |
| Z6C | Colorado | Anthem Blue-Cross Blue-Shield of Colorado |
| Z6D | California | Anthem Blue-Cross |
| Z6E | Wisconsin | Anthem Blue-Cross Blue-Shield of Wisconsin |
| Z6F | - | Prefix Unallocated/Not Assigned |
| Z6G | California | Anthem Blue-Cross |
| Z6H | California | Anthem Blue-Cross |
| Z6I | - | Prefix Unallocated/Not Assigned |
| Z6J | Connecticut | Anthem Blue-Cross Blue-Shield of Connecticut |
| Z6K | Connecticut | Anthem Blue-Cross Blue-Shield of Connecticut |
| Z6L | - | Prefix Unallocated/Not Assigned |
| Z6M | New Hampshire | Anthem Blue-Cross Blue-Shield of New Hampshire |
| Z6N | Alaska | Premera Blue-Cross Blue-Shield of Alaska |
| Z6O | - | Prefix Unallocated/Not Assigned |
| Z6P | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z6Q | - | Prefix Unallocated/Not Assigned |
| Z6R | Texas | Blue-Cross Blue-Shield of Texas |
| Z6S | Texas | Blue-Cross Blue-Shield of Texas |
| Z6T | Texas | Blue-Cross Blue-Shield of Texas |
| Z6U | - | Prefix Unallocated/Not Assigned |
| Z6V | - | Prefix Unallocated/Not Assigned |
| Z6W | Wisconsin | Anthem Blue-Cross Blue-Shield of Wisconsin |
| Z6X | - | Prefix Unallocated/Not Assigned |
| Z6Y | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| Z6Z | Wisconsin | Anthem Blue-Cross Blue-Shield of Wisconsin |
| Z7A | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7B | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7C | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7D | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7E | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7F | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7G | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7H | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7I | - | Prefix Unallocated/Not Assigned |
| Z7J | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7K | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z7L | Connecticut | Anthem Blue-Cross Blue-Shield of Connecticut |
| Z7M | Rhode Island | Blue-Cross Blue-Shield of Rhode Island |
| Z7N | - | Prefix Unallocated/Not Assigned |
| Z7O | - | Prefix Unallocated/Not Assigned |
| Z7P | - | Prefix Unallocated/Not Assigned |
| Z7Q | - | Prefix Unallocated/Not Assigned |
| Z7R | - | Prefix Unallocated/Not Assigned |
| Z7S | - | Prefix Unallocated/Not Assigned |
| Z7T | - | Prefix Unallocated/Not Assigned |
| Z7U | - | Prefix Unallocated/Not Assigned |
| Z7V | - | Prefix Unallocated/Not Assigned |
| Z7W | Wisconsin | Anthem Blue-Cross Blue-Shield of Wisconsin |
| Z7X | Wisconsin | Anthem Blue-Cross Blue-Shield of Wisconsin |
| Z7Y | - | Prefix Unallocated/Not Assigned |
| Z7Z | Wisconsin | Anthem Blue-Cross Blue-Shield of Wisconsin |
| Z8A | California | Anthem Blue-Cross |
| Z8B | - | Prefix Unallocated/Not Assigned |
| Z8C | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z8D | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z8E | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z8F | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| Z8G | - | Prefix Unallocated/Not Assigned |
| Z8H | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| Z8I | - | Prefix Unallocated/Not Assigned |
| Z8J | - | Prefix Unallocated/Not Assigned |
| Z8K | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| Z8L | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| Z8M | Arizona | Blue-Cross Blue-Shield of Arizona |
| Z8N | - | Prefix Unallocated/Not Assigned |
| Z8O | - | Prefix Unallocated/Not Assigned |
| Z8P | Alaska | Premera Blue-Cross Blue-Shield of Alaska |
| Z8Q | - | Prefix Unallocated/Not Assigned |
| Z8R | Alaska | Premera Blue-Cross Blue-Shield of Alaska |
| Z8S | - | Prefix Unallocated/Not Assigned |
| Z8T | - | Prefix Unallocated/Not Assigned |
| Z8U | - | Prefix Unallocated/Not Assigned |
| Z8V | - | Prefix Unallocated/Not Assigned |
| Z8W | - | Prefix Unallocated/Not Assigned |
| Z8X | - | Prefix Unallocated/Not Assigned |
| Z8Y | - | Prefix Unallocated/Not Assigned |
| Z8Z | - | Prefix Unallocated/Not Assigned |
| Z9A | New Hampshire | Anthem Blue-Cross Blue-Shield of New Hampshire |
| Z9B | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z9C | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z9D | Ohio | Anthem Blue-Cross Blue-Shield of Ohio |
| Z9E | - | Prefix Unallocated/Not Assigned |
| Z9F | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z9G | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z9H | Ohio | Anthem Blue-Cross Blue-Shield of Ohio |
| Z9I | - | Prefix Unallocated/Not Assigned |
| Z9J | - | Prefix Unallocated/Not Assigned |
| Z9K | Rhode Island | Blue-Cross Blue-Shield of Rhode Island |
| Z9L | - | Prefix Unallocated/Not Assigned |
| Z9M | California | Anthem Blue-Cross |
| Z9N | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z9O | - | Prefix Unallocated/Not Assigned |
| Z9P | - | Prefix Unallocated/Not Assigned |
| Z9Q | - | Prefix Unallocated/Not Assigned |
| Z9R | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| Z9S | California | Anthem Blue-Cross |
| Z9T | Connecticut | Anthem Blue-Cross Blue-Shield of Connecticut |
| Z9U | - | Prefix Unallocated/Not Assigned |
| Z9V | - | Prefix Unallocated/Not Assigned |
| Z9W | - | Prefix Unallocated/Not Assigned |
| Z9X | - | Prefix Unallocated/Not Assigned |
| Z9Y | - | Prefix Unallocated/Not Assigned |
| Z9Z | - | Prefix Unallocated/Not Assigned |