Secondary insurance can feel like a maze. Just when you think you’ve figured out one patient’s primary coverage, they casually mention a second—or even a third—insurance plan. What now?

In Chapter 9 of Understanding Dental Insurance, Dr. Travis Campbell tackles this confusing topic. While his insights are solid, the language can be complex for teams just trying to wrap their heads around the basics. So let’s break it down in plain English.

What Is Secondary Insurance?

Secondary insurance is a second dental plan a patient may have—often through a spouse or second job. It’s not meant to cover everything the first plan didn’t. Instead, it acts as a backup, sometimes picking up leftover costs but not always.

The Most Important Rule: Don't Double Dip

A common myth is that with two insurances, the patient gets “double coverage” or that a provider can bill both and get paid twice for the same service. That’s not how it works.

You can never collect more than 100% of your fee.

Think of it this way: if your fee is $200 for a filling and the primary insurance pays $120, the most you can expect from the secondary is $80—if that. Sometimes, it may pay less or nothing at all.

Coordination of Benefits (COB): The Rulebook

Coordination of Benefits (COB) determines who pays what. There are a few methods insurance companies use to figure this out:

1. Traditional COB (Standard Method)
   This is the most common. The secondary plan only pays what's left after the primary insurance pays, up to 100% of the allowed amount—not necessarily your fee. So if your fee is $200, and both plans allow $180, the secondary will consider what’s left after the primary pays its part.

2. Non-Duplication of Benefits
   This is tricky. If the secondary plan would have paid the same or less than the primary did, it pays nothing. So if both plans allow $150 and the primary already paid that, the secondary says, “All set!” and covers nothing.

3. Maintenance of Benefits
   This is a more rare method where the secondary reduces what it would pay by the amount the primary already paid, often resulting in a lower total benefit.

Bottom line: not all secondary insurance plans are created equal—and they don’t always pay.

Who Is Primary?

This gets especially confusing when both spouses have dental plans covering the same kids.

Use the Birthday Rule: Whichever parent’s birthday comes first in the calendar year (not who is older), their insurance is primary for the child.

If both plans are through the same employer or it’s unclear, call both companies. Let them duke it out—you just need the answer.

Why It Matters for Your Office

Here’s where it can hurt you: offices that try to estimate what the secondary will pay—based on what the primary didn’t—often overestimate. When the check arrives (or doesn’t), there’s a leftover balance. That leads to awkward phone calls with patients and unpaid revenue.

Dr. Campbell recommends this golden rule: Only estimate and collect based on primary insurance. Once you get the EOB (Explanation of Benefits) from the secondary, adjust the patient balance accordingly.

If you want to bill both plans, submit the claim to the primary, wait for the EOB, then submit to the secondary with a copy of that EOB. Yes, it’s extra work. But it’s the only way to do it right.

Pro Tip: Set Expectations Early

Train your team to explain to patients:

“We’re happy to bill your secondary insurance, but because every plan is different, we won’t know exactly what they’ll cover until after we hear from them. We’ll estimate based on your primary and adjust once both insurances respond.”

That one script alone can save you from a mountain of frustration and billing confusion.

In Summary

Secondary insurance doesn’t mean more money—it means more rules. The key takeaways from Dr. Campbell’s chapter are:

• Never expect more than 100% of your fee.

• Understand different COB methods.

• Know how to determine the primary plan.

• Always estimate based on the primary, not both.

• Communicate clearly with patients about what to expect.

When you simplify the approach and set clear expectations, secondary insurance doesn’t have to be a nightmare—it becomes just another part of running a savvy dental practice.

Benjamin Tuinei

Founder - Veritas Dental Resources, LLC
Phone: 888-808-4513

Services:
PPO Fee Negotiators | PPO Fee Negotiating | Insurance Fee Negotiating
Insurance Credentialing | Insurance Verifications

Websites:
www.VeritasDentalResources.com | www.VerusDental.com