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Dental insurance birthday rule
For a child covered by both parents, the parent whose birthday comes first in the calendar year usually holds the primary plan. Enter both birthdays to see which plan is primary — and when the rule doesn’t apply.
Parent A birthday
Parent B birthday
Primary plan for the child
Parent A's plan is primary
Parent A's birthday falls earlier in the calendar year, so Parent A's plan is the child's primary coverage.
A divorce decree or court order that assigns responsibility for the child's health coverage overrides the birthday rule. When parents are separated without a court order, the custodial parent's plan is usually primary. Always confirm the order of benefits with both carriers.
Once you know which plan is primary, run the claim through the coordination of benefits calculator to see what each plan pays and what the patient owes. Before you estimate dual coverage, capture eligibility, remaining benefits, and procedure-level limits in the dental insurance verification form.
Frequently asked questions
- What is the birthday rule for dental insurance?
- When a child is covered by both parents' dental plans, the birthday rule makes the plan of the parent whose birthday falls earlier in the calendar year the primary coverage. Only the month and day matter — not the birth year, so the older parent is not automatically primary.
- What if both parents have the same birthday?
- If both parents share the same month and day, the birthday rule can't break the tie. The plan that has covered the child longer is treated as primary. Confirm with both carriers.
- Does the birthday rule apply after a divorce?
- No. A divorce decree or custody order that assigns responsibility for the child's health coverage overrides the birthday rule. Without a court order, the custodial parent's plan is generally primary.