How Does It Work When You Have Two Health Insurance? 
When a family has two health insurance plans there are industry rules regarding which plan is considered primary . The rules may vary by state . The primary carrier pays the claim as if no other insurance was in place . The secondary carrier then pays any unpaid balances -LRB- deductibles , copays , coinsurance -RRB- in accordance with its plan design . The plan of the member is usually considered primary . When children are covered under two plans the birthday rule often applies . The plan covering the parent whose birthday occurs first in a calendar year is considered the primary plan . 