Final answer:
The Birthday Rule states that the parent with the earlier birthday in the calendar year has the primary insurance coverage for dependent children when both parents are not separated or divorced.
Step-by-step explanation:
The rule that indicates the father's coverage is primary for all dependent children of parents who are not separated or divorced is known as the Birthday Rule. The Birthday Rule is a guideline used by insurance companies to determine which parent's health insurance coverage will be considered primary for their children. According to this rule, the parent whose birthday (month and day, not year) comes first in the calendar year has the primary plan that will pay for the children's healthcare expenses first. It is important to note that this rule only applies when both parents have health insurance through their employers.