Nearly half of the 8.5 million U.S. children who lack health insurance have not seen a doctors or nurse for a medical check-up in the past year, according to a study published on Tuesday.

One third of uninsured children have no regular source of medical care such as a pediatrician, meaning they are probably going to be taken to an emergency room for routine needs, the study found.

“What these data tell us is what low-income working parents across this nation already know - that not having health insurance is bad for our nation’s children,” said Dr. John Lumpkin of the Robert Wood Johnson Foundation, which released the study.

“Without insurance too many children are missing the regular check-ups and preventive care that will prepare them to do their best in school. In this, the richest nation in the world, no child should be without health care coverage.”

The study by the Urban Institute used statistics from the Centers for Disease Control and Prevention to show that 48 percent of uninsured children had not had a well-child visit in the past year.

In comparison, 70 percent of children with private or public health insurance had a checkup in the past year, the report said. The American Academy of Pediatrics recommends that children get eight routine examinations by the time they are 2, in part to get key vaccinations.

Many, if not most of these uninsured children would be eligible for Medicaid or the State Children’s Health Insurance Program, the study found.

For the report, the Urban Institute analyzed data from the CDC’s National Health interview Survey of 40,000 people and 93,000 people, which is done every year.

The analysis includes information on 12,500 children and is considered representative of the U.S. population. It cites U.S. Census Bureau data to show that in 2002 there were 8.5 million uninsured children in the United States, or 11.6 percent of all children.

Medicaid and SCHIP provide at least 17 million children with coverage such as routine checkups, hearing and vision screenings, prescription medicines, and hospital care but parents may not know.

“I’ve met a lot of parents who were surprised to find out that their sons or daughters are eligible for these health care coverage programs,” said Virginia Governor Mark Warner, who is chairman of the National Governors Association.

“But in Virginia, and across the country, working families earning as much as $37,000 a year or more may be eligible.”