Adding or removing dependents updates the health insurance subscription effective the date of the change. Pro-rata premium for the days covered is captured through the reconciliation.
Adding or removing a dependent on an employee's health insurance policy updates the subscription effective the date of the change. The new state is reflected on your next subscription invoice issued on the 10th.
For the current month, if a dependent was added mid-month, you'll see a pro-rata premium for the days the dependent was covered, captured through the reconciliation alongside the $15 administration fee per policy that already applied.