| K2A | Texas | Blue-Cross Blue-Shield of Texas |
| K2B | Texas | Blue-Cross Blue-Shield of Texas |
| K2C | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| K2D | Illinois | Blue-Cross Blue-Shield of Illinois |
| K2E | California | Anthem Blue-Cross |
| K2F | Illinois | Blue-Cross Blue-Shield of Illinois |
| K2G | Oklahoma | Blue-Cross Blue-Shield of Oklahoma |
| K2H | New York (Western) | Blue-Cross Blue-Shield of Western New York |
| K2I | - | Unallocated/Not Assigned |
| K2J | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| K2K | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| K2L | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| K2M | New Jersey | Horizon Blue-Cross Blue-Shield of New Jersey |
| K2N | Vermont | Blue-Cross Blue-Shield of Vermont |
| K2O | - | Unallocated/Not Assigned |
| K2P | New Jersey | Horizon Blue-Cross Blue-Shield of New Jersey |
| K2Q | - | Unallocated/Not Assigned |
| K2R | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| K2S | Alaska | Premera Blue-Cross of Alaska |
| K2T | Minnesota | Blue-Cross Blue-Shield of Minnesota |
| K2U | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| K2V | Pennsylvania | Highmark Blue-Cross Blue-Shield of Pennsylvania |
| K2W | Kentucky | Anthem Blue-Cross Blue-Shield of Kentucky |
| K2X | Illinois | Blue-Cross Blue-Shield of Illinois |
| K2Y | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K2Z | Kentucky | Anthem Blue-Cross Blue-Shield of Kentucky |
| K3A | California | Anthem Blue-Cross |
| K3B | New York | Empire Blue-Cross Blue-Shield of New York |
| K3C | Virginia | Anthem Blue-Cross Blue-Shield of Virginia |
| K3D | - | Unallocated/Not Assigned |
| K3E | - | Unallocated/Not Assigned |
| K3F | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K3G | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| K3H | Pennsylvania | Highmark Blue-Shield of Pennsylvania |
| K3I | - | Unallocated/Not Assigned |
| K3J | - | Unallocated/Not Assigned |
| K3K | - | Unallocated/Not Assigned |
| K3L | Pennsylvania | Highmark Blue-Shield of Pennsylvania |
| K3M | California | Anthem Blue-Cross |
| K3N | Texas | Blue-Cross Blue-Shield of Texas |
| K3O | - | Unallocated/Not Assigned |
| K3P | Virginia | Anthem Blue-Cross Blue-Shield of Virginia |
| K3Q | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K3R | Pennsylvania | Highmark Blue-Shield of Pennsylvania |
| K3S | Alaska | Premera Blue-Cross of Alaska |
| K3T | California | Anthem Blue-Cross |
| K3U | Illinois | Blue-Cross Blue-Shield of Illinois |
| K3V | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| K3W | - | Unallocated/Not Assigned |
| K3X | - | Unallocated/Not Assigned |
| K3Y | - | Unallocated/Not Assigned |
| K3Z | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K4A | New York | Empire Blue-Cross Blue-Shield of New York |
| K4B | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K4C | Michigan | Blue-Cross Blue-Shield of Michigan |
| K4D | Ohio | Anthem Blue-Cross Blue-Shield of Ohio |
| K4E | - | Unallocated/Not Assigned |
| K4F | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| K4G | Maryland/District of Columbia/Northern Virginia | Carefirst Blue-Cross Blue-Shield |
| K4H | - | Unallocated/Not Assigned |
| K4I | - | Unallocated/Not Assigned |
| K4J | - | Unallocated/Not Assigned |
| K4K | - | Unallocated/Not Assigned |
| K4L | Ohio | Anthem Blue-Cross Blue-Shield of Ohio |
| K4M | New York | Empire Blue-Cross Blue-Shield of New York |
| K4N | Massachusetts | Blue-Cross Blue-Shield of Massachusetts |
| K4O | - | Unallocated/Not Assigned |
| K4P | - | Unallocated/Not Assigned |
| K4Q | - | Unallocated/Not Assigned |
| K4R | New York | Empire Blue-Cross Blue-Shield of New York |
| K4S | Massachusetts | Blue-Cross Blue-Shield of Massachusetts |
| K4T | Maryland/District of Columbia/Northern Virginia | Carefirst Blue-Cross Blue-Shield |
| K4U | Illinois | Blue-Cross Blue-Shield of Illinois |
| K4V | Texas | Blue-Cross Blue-Shield of Texas |
| K4W | - | Unallocated/Not Assigned |
| K4X | - | Unallocated/Not Assigned |
| K4Y | - | Unallocated/Not Assigned |
| K4Z | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K5A | California | Anthem Blue-Cross |
| K5B | Ohio | Anthem Blue-Cross Blue-Shield of Ohio |
| K5C | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K5D | Illinois | Blue-Cross Blue-Shield of Illinois |
| K5E | - | Unallocated/Not Assigned |
| K5F | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K5G | - | Unallocated/Not Assigned |
| K5H | - | Unallocated/Not Assigned |
| K5I | - | Unallocated/Not Assigned |
| K5J | - | Unallocated/Not Assigned |
| K5K | - | Unallocated/Not Assigned |
| K5L | - | Unallocated/Not Assigned |
| K5M | - | Unallocated/Not Assigned |
| K5N | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K5O | - | Unallocated/Not Assigned |
| K5P | Illinois | Blue-Cross Blue-Shield of Illinois |
| K5Q | - | Unallocated/Not Assigned |
| K5R | - | Unallocated/Not Assigned |
| K5S | - | Unallocated/Not Assigned |
| K5T | - | Unallocated/Not Assigned |
| K5U | - | Unallocated/Not Assigned |
| K5V | Texas | Blue-Cross Blue-Shield of Texas |
| K5W | - | Unallocated/Not Assigned |
| K5X | - | Unallocated/Not Assigned |
| K5Y | Kentucky | Anthem Blue-Cross Blue-Shield of Kentucky |
| K5Z | - | Unallocated/Not Assigned |
| K6A | New York | Empire Blue-Cross Blue-Shield of New York |
| K6B | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K6C | New York | Empire Blue-Cross Blue-Shield of New York |
| K6D | - | Unallocated/Not Assigned |
| K6E | - | Unallocated/Not Assigned |
| K6F | - | Unallocated/Not Assigned |
| K6G | - | Unallocated/Not Assigned |
| K6H | - | Unallocated/Not Assigned |
| K6I | - | Unallocated/Not Assigned |
| K6J | - | Unallocated/Not Assigned |
| K6K | - | Unallocated/Not Assigned |
| K6L | - | Unallocated/Not Assigned |
| K6M | Virginia | Anthem Blue-Cross Blue-Shield of Virginia |
| K6N | - | Unallocated/Not Assigned |
| K6O | - | Unallocated/Not Assigned |
| K6P | - | Unallocated/Not Assigned |
| K6Q | - | Unallocated/Not Assigned |
| K6R | - | Unallocated/Not Assigned |
| K6S | - | Unallocated/Not Assigned |
| K6T | - | Unallocated/Not Assigned |
| K6U | - | Unallocated/Not Assigned |
| K6V | - | Unallocated/Not Assigned |
| K6W | - | Unallocated/Not Assigned |
| K6X | - | Unallocated/Not Assigned |
| K6Y | - | Unallocated/Not Assigned |
| K6Z | - | Unallocated/Not Assigned |
| K7A | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7B | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7C | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7D | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7E | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7F | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7G | - | Unallocated/Not Assigned |
| K7H | - | Unallocated/Not Assigned |
| K7I | - | Unallocated/Not Assigned |
| K7J | - | Unallocated/Not Assigned |
| K7K | - | Unallocated/Not Assigned |
| K7L | - | Unallocated/Not Assigned |
| K7M | Ohio | Anthem Blue-Cross Blue-Shield of Ohio |
| K7N | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K7O | - | Unallocated/Not Assigned |
| K7P | - | Unallocated/Not Assigned |
| K7Q | - | Unallocated/Not Assigned |
| K7R | - | Unallocated/Not Assigned |
| K7S | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| K7T | - | Unallocated/Not Assigned |
| K7U | - | Unallocated/Not Assigned |
| K7V | - | Unallocated/Not Assigned |
| K7W | - | Unallocated/Not Assigned |
| K7X | Texas | Blue-Cross Blue-Shield of Texas |
| K7Y | - | Unallocated/Not Assigned |
| K7Z | - | Unallocated/Not Assigned |
| K8A | Colorado | Anthem Blue-Cross Blue-Shield of Colorado |
| K8B | - | Unallocated/Not Assigned |
| K8C | California | Anthem Blue-Cross |
| K8D | - | Unallocated/Not Assigned |
| K8E | - | Unallocated/Not Assigned |
| K8F | - | Unallocated/Not Assigned |
| K8G | - | Unallocated/Not Assigned |
| K8H | - | Unallocated/Not Assigned |
| K8I | - | Unallocated/Not Assigned |
| K8J | - | Unallocated/Not Assigned |
| K8K | - | Unallocated/Not Assigned |
| K8L | - | Unallocated/Not Assigned |
| K8M | California | Anthem Blue-Cross |
| K8N | - | Unallocated/Not Assigned |
| K8O | - | Unallocated/Not Assigned |
| K8P | Texas | Blue-Cross Blue-Shield of Texas |
| K8Q | - | Unallocated/Not Assigned |
| K8R | - | Unallocated/Not Assigned |
| K8S | - | Unallocated/Not Assigned |
| K8T | - | Unallocated/Not Assigned |
| K8U | - | Unallocated/Not Assigned |
| K8V | - | Unallocated/Not Assigned |
| K8W | - | Unallocated/Not Assigned |
| K8X | - | Unallocated/Not Assigned |
| K8Y | Arizona | Blue-Cross Blue-Shield of Arizona |
| K8Z | Arizona | Blue-Cross Blue-Shield of Arizona |
| K9A | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K9B | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K9C | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K9D | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K9E | - | Unallocated/Not Assigned |
| K9F | - | Unallocated/Not Assigned |
| K9G | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K9H | - | Unallocated/Not Assigned |
| K9I | - | Unallocated/Not Assigned |
| K9J | - | Unallocated/Not Assigned |
| K9K | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K9L | - | Unallocated/Not Assigned |
| K9M | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K9N | Georgia | Anthem Blue-Cross Blue-Shield of Georgia |
| K9O | - | Unallocated/Not Assigned |
| K9P | - | Unallocated/Not Assigned |
| K9Q | - | Unallocated/Not Assigned |
| K9R | - | Unallocated/Not Assigned |
| K9S | - | Unallocated/Not Assigned |
| K9T | - | Unallocated/Not Assigned |
| K9U | - | Unallocated/Not Assigned |
| K9V | - | Unallocated/Not Assigned |
| K9W | Indiana | Anthem Blue-Cross Blue-Shield of Indiana |
| K9X | - | Unallocated/Not Assigned |
| K9Y | Oregon/Idaho/Utah/Washington | Regence Blue-Cross Blue-Shield |
| K9Z | - | Unallocated/Not Assigned |