Sources and methodology
Last reviewed
Unofficial reference. Prefixes change. Verify with the plan before submitting a claim.
AlphaPrefix currently lists 859 prefixes under 47 plan names, taken from 59 source documents. The entries include at least one prefix for plans in 37 states plus DC. Entries for plans listed as multi-state are not counted toward any state. Coverage is uneven: a large share of the entries comes from a few plans that publish full prefix lists (the 3 plan names with the most entries account for 59% of them), and many plans have few or no entries. Data last updated .
These counts are computed from our data each time the site is built. Plan names are counted as the sources state them, and several can belong to one company (regional names or product lines), so the number of plan names is not the number of separate Blue companies.
Coverage by plan name
Number of prefixes we list under each plan name, largest first, from 59 source documents.
| Plan name | Prefixes |
|---|---|
| Premera Blue Cross | 418 |
| CBA Blue | 48 |
| CareFirst BlueCross BlueShield | 47 |
| Independence Blue Cross | 46 |
| Premera Blue Cross/Shared Admin | 25 |
| Blue Cross and Blue Shield of Montana | 24 |
| Anthem Blue Cross and Blue Shield (Connecticut) | 22 |
| Anthem Blue Cross and Blue Shield (Kentucky) | 19 |
| Blue Cross and Blue Shield of Louisiana | 19 |
| Blue Cross and Blue Shield of Vermont | 16 |
| Blue Cross and Blue Shield of Illinois | 15 |
| Anthem Blue Cross and Blue Shield (Maine) | 14 |
| Premera Blue Cross HMO | 13 |
| Blue Cross Blue Shield of Michigan | 12 |
| BlueCross BlueShield of Tennessee | 11 |
| Blue Cross & Blue Shield of Rhode Island | 10 |
| Blue Cross Blue Shield of Wyoming | 10 |
| BlueCross BlueShield of South Carolina | 10 |
| Blue Cross and Blue Shield of Texas | 9 |
| Blue Care Network of Michigan | 8 |
| Anthem Blue Cross and Blue Shield (New Hampshire) | 7 |
| Blue Cross and Blue Shield of Kansas | 7 |
| BlueChoice HealthPlan of South Carolina | 6 |
| Anthem Blue Cross and Blue Shield (Colorado) | 4 |
| Blue Cross and Blue Shield of North Carolina | 4 |
| Empire BlueCross BlueShield | 4 |
| Horizon (New Jersey State Health Benefits Program) | 3 |
| Anthem Blue Cross | 2 |
| Anthem Blue Cross and Blue Shield (Indiana) | 2 |
| Blue Cross and Blue Shield of Minnesota | 2 |
| Blue Cross and Blue Shield of Nebraska | 2 |
| Blue Cross and Blue Shield of New Mexico | 2 |
| Highmark Blue Cross Blue Shield (Western and Northeastern New York) | 2 |
| Regence BlueCross BlueShield of Utah | 2 |
| Wellmark Blue Cross and Blue Shield | 2 |
| Anthem Blue Cross and Blue Shield (Missouri) | 1 |
| Anthem Blue Cross and Blue Shield (New York) | 1 |
| Anthem Blue Cross and Blue Shield (Virginia) | 1 |
| Anthem Blue Cross and Blue Shield (Wisconsin) | 1 |
| Anthem Blue Cross and Blue Shield HP | 1 |
| Blue Cross and Blue Shield of Alabama | 1 |
| Blue Cross Blue Shield of Massachusetts | 1 |
| Blue Cross Blue Shield of North Dakota | 1 |
| Blue Cross NC (Healthy Blue Care Together) | 1 |
| Capital Blue Cross | 1 |
| CareFirst BlueCross BlueShield Community Health Plan Maryland | 1 |
| Truli for Health (affiliate of Florida Blue) | 1 |
Where entries come from
We compile entries only from official, public sources:
- Blue plans' own public documents, such as provider manuals, provider news and bulletins, ID card guides and quick reference guides
- bcbs.com
- .gov websites
- Benefit pages from large employers, universities or unions that state the prefix of their own plan
We never use third-party prefix lists, billing blogs, forums or similar compilations, even when they appear to agree with an official source.
What every entry records
Each prefix entry stores:
- The plan name as the source states it, the state, and the plan type and notes when the source gives them
- The URL and title of the official source, and the source's own date when it shows one
- The date we last checked the entry against the source
- The exact text from the source that supports the entry. We keep it on file for checking; it is not shown on the site.
A phone number for providers is shown only when the source prints it alongside the prefix and the source is dated 2022 or later. Plan website links for providers are not populated at launch, so entries do not show one. You can open the source from any entry and check it yourself.
Rules we follow
- Nothing is inferred. An entry appears only if an official source states the prefix and the plan. We do not guess from patterns, neighboring prefixes, employer names or plan locations.
- Conflicts are left out. When official sources disagree about a prefix, we leave that prefix out until the conflict is resolved.
- Older sources are flagged. If an entry's source is dated before 2022, the entry shows a "Source dated before 2022" flag so you know to take extra care. Some sources show no date; those entries are not flagged, so check the source.
- Coverage is partial. There are many more prefixes in use than we list. Some Blue plans have no entries in our data yet, and others have only a few. A prefix not found here may still be valid. See Prefix not found.
How the dates work
Each entry shows a "Last checked" date: the day we last opened the source and confirmed that it still supports the entry. When we re-check an entry and it still holds, only that date changes. If the source has changed, we update the entry or remove it. "Data last updated", shown next to every result and table, is the most recent "Last checked" date across all entries. It does not mean every entry was checked on that day.
Guides
Our guides draw only on Blue plans' public provider materials, bcbs.com and fepblue.org. Each guide lists the sources it relies on and the date it was last reviewed.
Report a correction
If you find an error, or you have an official source for a prefix we do not list, email corrections@alphaprefix.com with the prefix, the correct plan and a link to the official source. Never include member IDs or patient information. Details are on our Corrections page.