Coordination of benefits: which plan pays first when you have 2

You have 2 health plans, so you expected less to pay. Instead, a claim was denied, or a bill shows the full price. The explanation of benefits (EOB) may say another plan should pay first.

This is a coordination of benefits problem, and it's usually fixable. It's part of our guide on how to appeal an insurance denial, though most of these denials don't need an appeal at all.

How does coordination of benefits work?

When 2 plans cover the same person, they don't each pay the full claim. One plan is primary and pays first, up to its limits. The other is secondary. It may then pay some or all of what's left, based on its own terms.

Together, the plans won't pay more than the cost of your covered care. If the secondary plan doesn't cover the rest, you may owe it.

Why do coordination of benefits errors happen?

Most of these problems come from missing or old information, not from a decision about your care. Common causes:

• Your plan doesn't know about your other coverage. Many plans ask about other coverage once a year. If you don't answer, a plan may deny claims until you do.
• The provider billed the plans in the wrong order. The secondary plan gets the claim first and sends it back.
• The secondary plan never saw the primary plan's EOB. It can't figure out its share without knowing what the first plan paid.
• Your coverage changed. A new job, a retirement, a divorce, or Medicare can change which plan is primary.
• Medicare's records are out of date. Medicare may think another plan should pay first, or the reverse.
• The 2 plans disagree. Each one says the other should pay first.

On your EOB, these problems often show up as claim adjustment reason code 22. The official meaning is that another plan may cover the care under coordination of benefits rules. Our guide to denial codes on your EOB explains how to read the rest of the code.

Which plan pays first?

Most states base their rules on a model from the National Association of Insurance Commissioners (NAIC). Self-funded employer plans set their own rules, and many use similar ones. Each plan uses the first rule on this list that fits.

The birthday rule only counts the month and day. So a parent born on March 14 has a birthday before one born on August 2, whatever their ages.

Your plan's coordination of benefits section has the exact rules. Ask for your plan documents if you're not sure. Our guide to self-funded vs. fully insured plans explains which kind you have.

Who pays first when you have Medicare?

Federal rules decide the order when Medicare is involved. Here are the most common cases.

What is the coordination of benefits questionnaire?

It's a short form, letter, or online question asking whether anyone in your family has other health coverage. Plans use the answers to decide who pays first.

Answer it even if you only have 1 plan. A blank answer can hold up claims just like a wrong one. You can often answer by phone or in your plan's app.

Medicare has its own version, called the Medicare Secondary Claim Development Questionnaire. It may come after a claim shows another plan's EOB, or after someone reports other coverage.

Say Maya's son is covered by her plan and her husband's plan. Maya was born on March 14, and her husband on August 2. Under the birthday rule, Maya's plan pays first.

The urgent care clinic billed her husband's plan first. It denied the $400 claim with code 22, and the clinic billed Maya the full $400. She called both plans to confirm the order. Then she asked the clinic to rebill her plan first.

	Before the fix	After the fix
Amount billed	$400	$400
Network discount	$0	$100
Maya's plan paid (80% of $300)	$0	$240
Husband's plan paid	$0	$60
Maya owes	$400	$0

Her plan's allowed amount was $300, so the network discount is $100. Her plan paid 80% of $300, which is $240, and left $60. Her husband's plan would have paid $252 as primary. That's more than the $60 left, so it covered the $60. And $400 − $100 − $240 − $60 = $0.

Secondary plans don't always cover the whole balance. It depends on each plan's terms.

What to do about a coordination of benefits denial

1. Figure out which plan is primary. Use the tables above, then call both plans to confirm. Ask each one which rule it used.
2. Update your other coverage with every plan. Answer the questionnaire, or tell member services by phone. If you have Medicare, call the Benefits Coordination & Recovery Center at 1-855-798-2627 (TTY 1-855-797-2627).
3. Give the provider both plans, in order. Ask the billing office to bill the primary plan first. Then ask them to send the secondary plan the claim with the primary plan's EOB.
4. Ask for a hold. Ask the billing office to pause your account while the claims are reprocessed.
5. Check the new EOBs. Compare them with your bill, line by line. Our guide on an EOB vs. a medical bill shows how.
6. Put it in writing if the plans disagree. Ask each plan to explain its decision in writing. If a plan still won't pay, you can appeal its decision.

Our guide to what to do when insurance didn't pay a medical bill covers other reasons a claim gets stuck.

When to get help

You can fix most coordination of benefits problems with a few calls. It's worth getting help when:

• Both plans say the other one should pay first.
• A plan keeps denying claims after you've updated your coverage.
• The bill has gone to collections while the plans sort it out.
• You're managing coverage for a parent with Medicare and other insurance.

Start with member services, using the number on each insurance card. Your state insurance department can help with fully insured and Marketplace plans. For employer plans, the Department of Labor's Employee Benefits Security Administration answers questions at 1-866-444-3272.

If you have Medicare, call 1-800-MEDICARE (1-800-633-4227), or get free counseling from your State Health Insurance Assistance Program. A medical bill advocate can also make the calls for you.