Dual Coverage

"Dual coverage" refers to when a patient's dental treatment is covered by more than one dental benefits plan.

"Coordination of benefits" is the process insurance companies follow to ensure that the combined benefits from all group dental plans do not exceed 100 percent of the dentist’s fee.

Information to Include on Dual Coverage Claims:

  • ID numbers for Both Covered Enrollees
  • Patient’s relationship to each enrollee
  • Birth date for the patient and each enrollee
  • If parents are divorced, the parent with whom the child lives
  • When Delta Dental is the secondary carrier, Explanation of Benefits (EOB) from the primary carrier

Determining the Primary Plan

For adults, the enrollee’s plan through his or her employment is primary. A spouse or domestic partner’s plan is secondary.

In less common situations, an enrollee may have two plans, such as a plan through current employment and a retiree plan. In this case, generally, the plan through current employment is primary. If the enrollee has two plans through current employment at two jobs, then the plan that has been in effect the longest is usually primary. However, specific plan provisions may dictate differently how dual coverage will be determined, so it is a good idea to check the enrollee’s Evidence of Coverage for details.

For dependent children, follow the birthday rule (rather than the gender rule). The parent whose birthday falls earlier in the year holds the primary coverage for dependent children. The year is not relevant. These rules may be superseded by a court order that establishes the responsible party for the child’s coverage.


If the father’s birth date is 10/3/67 and the mother’s birth date is 5/15/68, then the mother’s coverage is primary.

Divorce and Remarriage

Please use the following general claims submission guidelines (unless there are other circumstances, such as a court order, that specify primary coverage):

  • Primary coverage – natural parent with custody
  • Secondary coverage – step-parent with custody
  • Third coverage – natural parent without custody
  • Fourth coverage – step-parent without custody

Dual Coverage Status Changes

Be sure to regularly review and update your patients’ dual coverage status. Patients may change their coverage, usually in the fall or spring, during their open enrollment periods.

If a patient no longer has dual coverage, please write “patient no longer covered by another plan” on the claim form (or in the comments/remarks field of an electronic claim) to help ensure correct payment and updating of Delta Dental’s records.

Dual Coverage with the Same Delta Dental Company

A patient may have dual coverage through the same Delta Dental company (for example, your patient may have her own Delta Dental of California coverage and also be covered as a spouse through her husband’s plan, which is also a Delta Dental of California plan).

When this occurs, please submit only one claim to the Delta Dental company. Delta Dental will process the primary benefits, even if processing the secondary coverage must be delayed (for lack of eligibility data, for example). There is no need to resubmit the claim. You will be notified separately when processing of secondary coverage is completed.

Orthodontic Services

Be sure to submit dual coverage information on claims for orthodontic procedures, even if the other insurance does not cover orthodontics. This is important because some services may be included in the patient’s basic coverage, even if the patient does not have specific orthodontic coverage. Also, this will help ensure that Delta Dental’s calculation of the patient’s portion takes into account all available benefit information.

California Rule for Coordination of Benefits

When Delta Dental of California is the secondary carrier and is subject to the provisions of the California Health and Safety Code §1374.19, we pay the lesser of: (1) the amount we would have paid in the absence of any other dental benefit coverage; or (2) the enrollee’s out-of-pocket cost payable under the primary plan for benefits that are covered by the secondary plan.

Please indicate the total amount paid by the primary carrier on the face of a paper claim or in the comments/notes section of an electronic claim and attach a copy of the Explanation of Benefits from the primary carrier.

The combined payments by all plans may not exceed the total fee for the treatment. If you or the patient receives more than 100 percent of the fee, the amount in excess should be refunded to the secondary carrier.

Non-duplication of Benefits

Some Delta Dental groups that are not subject to the provisions of California Health and Safety Code §1374.19 have a non-duplication of benefits clause in their contract.

Such clauses means that the secondary plan will not pay any benefits if the primary plan paid the same or more than what the secondary plan allows for that dentist.

For example, if both the primary and secondary carrier pay for the service at 80 percent level but the primary allows $100 and the secondary carrier normally allows $80 for the same treatment, the secondary carrier would not make any additional payment. However, if the primary carrier only pays 50 percent of the dentist’s allowed fee, then the secondary carrier would reduce its payment by the amount paid by the primary plan and pay the difference. In this case, the secondary carrier would pay $14 ($80 x 80 percent - $50 = $14).