When a patient has two insurance plans, you need to know which pays first.
That is coordination of benefits (COB). Get COB wrong and your claim is denied or reprocessed, delaying payment.
What COB Is
COB is the order in which insurance companies pay when a patient has multiple plans.
Patient has their own insurance (primary). Spouse has insurance too, and patient is covered as a dependent (secondary).
When the patient has a dental procedure:
- Primary insurance pays first
- Secondary insurance pays the remaining balance (up to their benefit limit)
- Patient pays any remaining balance
Common COB Scenarios
Employee with spouse coverage: Employee’s insurance is primary. Spouse’s insurance is secondary.
Dependent with parent coverage and own coverage: Parent’s insurance is primary if the dependent lives with them. The dependent’s own insurance is secondary.
Government coverage with private insurance: Private insurance is usually primary. Medicare is usually secondary.
Determining COB
Coordination of benefits rules are complicated. The general rule:
The plan that covers the employee is primary. The plan that covers them as a dependent is secondary.
But there are exceptions. The plan that has been covering them the longest might be primary. Or the plan with the birthday rule (parent born earlier in the year is primary) applies.
You need to verify COB with each insurance company.
Getting COB Right
Step 1: Ask the patient about their insurance situation.
“Do you have other insurance coverage? Is anyone else’s insurance covering you?”
Step 2: Get both insurance cards.
Step 3: Call both insurance companies.
“This patient is covered under both Plan A and Plan B. Which is primary?”
Step 4: Document which is primary and which is secondary.
Step 5: When submitting claims, reference both plans with the correct COB order.
Step 6: After the primary insurance pays, submit remaining balance to secondary insurance.
Why COB Mistakes Cause Denials
You submit to secondary insurance first. Secondary says “This is not primary. Deny.” You have to resubmit to primary first. Delay. Frustration.
You claim that primary insurance paid more than it should have. But you submitted wrong COB order. Now there is a dispute over who owes what.
Reach Handles COB
Reach team members trained in COB verification:
- Ask about secondary insurance during initial call
- Get both insurance cards
- Verify COB with both insurance companies
- Document in the patient chart
- Submit claims in correct COB order
Secondary insurance is handled as a separate step, not an afterthought.
AI-Amplified COB
HIPAA-grade AI tools:
- Alert when a patient has multiple insurance
- Track COB order (primary vs. secondary)
- Ensure correct claim submission sequence
- Follow up on secondary claims after primary pays
FAQ
**Q: What if the two insurance companies disagree on COB?**
A: This happens. Document both companies’ statements. Usually the plan that has been covering them longest is primary.
**Q: Do I have to bill secondary insurance?**
A: No. You can leave it to the patient. But billing secondary typically gets you paid faster and leaves patient with lower responsibility.
**Q: What if secondary insurance is with a Medicaid plan?**
A: Medicaid is almost always secondary to private insurance.
**Q: How much does secondary insurance typically pay?**
A: Depends on their coverage. Could be 20-50% of remaining balance after primary pays.
**Q: What if the patient does not disclose secondary insurance?**
A: Document that you asked. If insurance claims are later submitted, note that patient did not disclose.