Member ID Prefixes

Most BCBS member IDs start with a three-character prefix. FEP member IDs start with the letter R.
  • 2023 January-Current (Excel)

    Previous versions:
    2022 July (PDF)
    2022 April (PDF)
    2022 January (PDF)
    2021 July (PDF)

  • BCBSAZ has updated member accounts and replaced prefixes for certain members. This table shows the replacements. Keep in mind, members may also change their place of employment or switch to a different plan type. This may also result in a member ID change.

  • Effective January 1, 2023, some BCBSAZ member accounts were updated with new member ID prefixes. This may require adjustments in your eligibility/benefits inquiries and claim submission processes to ensure accurate information and timely claim processing. For more information, see our provider FAQs.

    Tip: Be sure to submit eligibility/benefits inquiries and claims with the prefix related to the date of service.
    If you do an eligibility/benefits inquiry using a prefix that isn’t valid for the service date, you will receive a “Member Not Found” message that may not be accurate for that member. You can re-run your inquiry using the other prefix or use the “Name” search option to bypass the need to enter a prefix. If you can’t confirm eligibility online, please email us at so we can validate the member’s eligibility.

    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 and where to find the prefix reference list so you can resubmit your claim with the other prefix:

    "This member's ID prefix was replaced. Please check the prefix listed and resubmit with the prefix that is valid for this service date."

    Tip: You might want to adjust the date range of your online remit searches.

    Some member accounts will be updated without a prefix replacement. All account updates (with and without prefix replacements) may affect remit searches that span a date range. If you find remits are missing from your search, try searching payments issued up to the date of the account update (e.g., 01/01/2023) and do another search for payments issued on or after that date.

    Note: For Federal Employee Program® (FEP®) members (prefix “R”), use the following 2022 dates to start or end your remit searches:

    • August 6, 2022 (dental claims)
    • October 29, 2022 (professional claims)
    • November 19, 2022 (institutional claims)
  • In addition to routing claims and electronic inquiries, BCBS member ID prefixes indicate specific network and benefit plan information. Most prefixes are in the first three positions of the member's ID number and can be a mix of alpha and numeric characters. 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 specific instructions to verify eligibility, submit claims, and contact customer service.