Coinsurance in Dental Insurance: What Practices Need to Know

Understanding who pays what is a fundamental part of dental insurance verification.

A patient may have active coverage, but that does not necessarily mean their insurance will pay the full cost of treatment. Coinsurance determines how the cost of a covered procedure is shared between the insurance plan and the patient.

For dental practices, correctly verifying coinsurance is essential for providing accurate patient estimates and avoiding unexpected balances after treatment.

What Is Coinsurance?

Coinsurance is the percentage of a covered dental procedure that the patient is responsible for paying, while the insurance company pays the remaining covered percentage after any applicable deductible has been met.

For example, if a dental plan covers basic services at 80%, the patient is generally responsible for the remaining 20%.

That 20% is the patient's coinsurance.

A Simple Example

Consider a filling that costs $200, with the plan covering basic services at 80%.

Insurance pays: $160 (80%) Patient pays: $40 (20%)

In this example, the patient's coinsurance is 20%.

While the calculation itself is simple, identifying the correct coverage percentage during verification is critical.

Coinsurance Varies by Service Category

Dental plans may apply different coverage percentages depending on the type of treatment.

A typical benefit structure may look like this:

Service Category	Insurance Coverage	Patient Coinsurance
Preventive – Cleanings & Exams	100%	0%
Basic – Fillings, Endo, Perio & Simple Extractions	80%	20%
Major – Crowns, Dentures & Implants	50%	50%

These percentages can vary by plan, which is why they should be confirmed during insurance verification rather than assumed.

While Endodontics (Endo), Periodontics (Perio), and Extractions are commonly classified as Basic services, some dental plans may classify them under Major services instead.

Why Coinsurance Matters During Verification

Knowing that a procedure is covered is only part of the picture.

Practices also need to understand how much of that procedure the insurance plan is expected to cover and how much may become the patient's responsibility.

Accurately verifying coinsurance helps practices:

• Provide more accurate patient estimates

• Communicate expected out-of-pocket costs before treatment

• Reduce unexpected patient balances

• Improve billing and collection processes

• Create a better patient experience

Don't Overlook the Deductible

Coinsurance should not be viewed in isolation.

Depending on the patient's plan, an applicable deductible may need to be met before the insurance coverage percentage applies.

This means that simply seeing “80% coverage” does not always mean the insurance company will immediately pay 80% of the treatment cost.

Both the deductible and coinsurance should be reviewed when estimating patient responsibility.

Getting the Percentage Right Matters

A small error in the coverage percentage can create a significant difference in the patient's estimate particularly with higher-cost procedures.

That's why accurate insurance verification goes beyond confirming whether coverage is active. It requires understanding the benefit structure for the specific services being provided.

Final Thoughts

Coinsurance may appear to be a simple percentage, but it plays an important role in determining patient financial responsibility.

Understanding and accurately verifying coinsurance helps dental practices provide clearer estimates, minimize billing surprises, and improve financial conversations with patients.

Because when it comes to dental insurance, knowing that a procedure is covered isn't enough, knowing who pays what matters just as much.