What does the "birthday rule" determine in the context of insurance for a child with multiple policies?

The "birthday rule" is a guideline used to determine which parent's health insurance policy will be primary when a child is covered by both parents' plans. According to this rule, the policy from the parent whose birthday falls earlier in the calendar year is considered the primary insurance. This approach is intended to simplify coordination of benefits and ensure clarity regarding which insurer is responsible for payment.

By using the birth month rather than the age or coverage limits of the parents' policies, the birthday rule helps avoid confusion and establishes a straightforward way to identify the primary plan. This is especially useful in situations where both parents have insurance coverage for the child, as it provides a consistent method for identifying the responsible party for medical claims.

Some options may suggest alternative criteria for determining priority, such as coverage limits or the employer's size, but these are not utilized within the framework of the birthday rule. This method emphasizes the importance of the birth date, making it a widely accepted standard in the realm of health insurance for dependents.