When enrolling a dependent during initial or open enrollment periods, dependents will have the same effective date as the employee enrolling.

When enrolling a dependent during initial or open enrollment periods, dependents will have the same effective date as the employee enrolling.
When enrolling a dependent due to a qualifying life event, the effective date is usually the first of the month following the qualifying event. In some circumstances, the carrier may allow a mid-month effective date, but those are much less common.