Starting a family is a decision that has huge costs on a family’s financial burden. Luckily, insurance coverage does ease the burden. However, there is a little-known rule called the ‘birthday rule’ that has a bearing on which parent’s insurance will pay for the baby’s delivery and the first month of life.

Being unaware of this rule created financial stress for a Highland Park couple that cost them thousands of dollars.

Bowie Tinio, 20-month-old now, was severely anemic at birth.

"He was probably losing blood in the womb," Bowie's father, Mike Tinio said, ABC7 reported.

"It was a complicated delivery. He actually ended up in the NICU for four days," Vanessa Ying, Bowie's mother added.

Those four days in the neonatal intensive care unit lead to a bill of $80,000. Ying said that she was told that the first month of a baby's life is covered under the mother's policy so she increased her insurance benefits in case of an emergency.

"She made sure she got the best insurance that she could get, " Tinio said.

However, two months later, the couple received medical bills to the tune of $10,000.

I was really confused. I thought we had paid all our hospital bills so I didn't know why we were getting some additional bills," Ying said.

Eventually, Ying found out her insurance company did not cover the cost of the delivery coverage and instead her husband's insurance plan was being considered because of the "birthday rule."

The birthday rule is an insurance practice used to determine the plan which will be used to cover the cost of the baby’s delivery when both parents have insurance.

"It's not made to make life better for consumers," Professor Glenn Melnick with USC's Sol Price School of Public Policy said.

According to the rule, the insurance plan of the parent whose birthday comes up first in a calendar year will cover the cost of the pregnancy, irrespective of the year one was born. So, age is not a factor in this, as per EHealthInsurance.

“So if my birthday is in January and my wife's in February, then the children get assigned to my policy in January because my birthday comes up first in the year. There's this hidden trap that can end up costing them thousands if not tens of thousands of dollars," Melnick said.

For bowie’s parents, it was a difference of about $7,000. Melnick advised new parents with dual coverage should research the insurance policies.

"You're not getting double coverage because of the birthday rule and so you should figure out which policy is the best one," he said.

After 20 months, with help from an advocate in Ying's human resources office, Ying's insurance company agreed to pay, which put a stop to the collection calls.

"If at all possible, just be on the same insurance plan," Melnick suggested.