Member ID Prefixes

Most BCBS member IDs start with a three-character prefix. FEP member IDs start with the letter R.

  • 2024 List - Effective 7/1/24 (Excel)

    Previous versions:
    2024 June (Excel)
    2024 January (Excel)
    2023 January (Excel)

  • BCBS member ID prefixes are used to quickly route claims and electronic inquires. Prefixes may also indicate specific network and benefit plan information. Most prefixes are the first three characters of the member ID and may be a mix of letters and numbers (e.g., P9H, 99D, Y4M, Z9P). FEP plans use just the letter “R” as the prefix. If an ID does not include a prefix, please check the back of the card for instructions on validating eligibility, submitting claims, and contacting customer service.

  • AZ Blue sometimes updates member accounts and replaces a member ID prefix. The table below shows prefix replacements. It’s important to use the correct prefix for the date of service in your transactions. Another reason member IDs or prefixes may change is when members change their place of employment or switch to a different plan type.

  • Using the member ID prefix that corresponds to the date of service is critical for timely claim processing, as well as accurate information for eligibility and benefits.

    • If you do an eligibility/benefits inquiry using a prefix that isn’t valid for the service date, you may receive a “Member Not Found” message that may not be accurate for that member.
    • If you submit a claim using a prefix that isn’t valid for the service date, you will receive a message advising you of the prefix replacement:

    “This member’s ID prefix was replaced. Please check the prefix list at azblue.com/prefix and resubmit with the prefix that is valid for this service date.”