C3X BCBS Prefix
Member IDs beginning with C3X belong to Anthem Blue-Cross Blue-Shield of Wisconsin — the Blue plan for Wisconsin.
- Alpha prefix
- C3X
- Home plan
- Anthem Blue-Cross Blue-Shield of Wisconsin
- State
- Wisconsin
- BlueCard eligibility
- 1-800-676-BLUE (2583)
Billing a patient with a C3X member ID
- 1
Verify eligibility through Anthem Blue-Cross Blue-Shield of Wisconsin 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 Anthem Blue-Cross Blue-Shield of Wisconsin through the BlueCard® program. Include the full member ID with the C3X 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.
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