Have two health insurance plans? Make sure both were billed
Coordination of benefits is how two health plans decide which one pays first and how much the second one pays. When you have two plans, the second often pays some or all of what the first leaves. Here's how to check it was billed.
Updated October 5, 2026 · 1 min read
The short version
- With two plans, the second may pay some or all of what the first leaves.
- If you only have one EOB for the visit, the second plan may not have been billed.
- Ask billing to bill it, and to hold the account until it's processed.
If you're covered by two plans (for example your job and a spouse's, or Medicare and a supplement), one pays first and the other may pay some or all of what's left. If the provider only billed the first plan, you might be billed for money the second plan would have paid.
How can you tell if both plans were billed?
- Look for an EOB from each plan for the same visit.
- If you only have one EOB, the second plan may not have been billed.
- Your bill may say "secondary billed" or "pending secondary" if it was.
“I have two insurance plans. Do you have [second plan] on file for my visit on [date], and was it billed? If not, I'll give you the details now. Please hold the account until the second plan has processed the claim.”
Your insurers may send a coordination-of-benefits form asking about other coverage. Answering it quickly helps prevent denials. This guide is educational, not legal advice.
Educational information only, not legal, medical or financial advice. Rules vary by state and plan.