E4B BCBS Prefix

Member IDs beginning with E4B belong to BCBS of Massachusetts — the Blue plan for Massachusetts.

Billing a patient with a E4B member ID

1
Verify eligibility through BCBS of Massachusetts or the BlueCard eligibility line before the visit — coverage and benefits are governed by the member's home plan.
2
Submit the claim to your local Blue plan, which routes it to BCBS of Massachusetts through the BlueCard® program. Include the full member ID with the E4B prefix exactly as printed on the card.
3
Track timely filing against the home plan's rules — BCBS filing limits vary by plan and contract, so check our timely filing limits directory and confirm the window that applies to your participation status.
4
If the claim denies for eligibility or wrong payer, re-verify the prefix — members change plans often and old cards stay in circulation.

Prefix assignments change without notice. Always confirm with the payer or the member's current ID card before filing.

Eligibility, clean claims, denials, and AR — free audit shows what you're missing.