There are more than 2 million American children who don’t have health insurance, yet at least one of their parents is covered by employer-provided insurance, Reuters reported.

This is because their parents cannot afford the extra thousands of dollars it costs to insure the child, said researchers in the Journal of the American Medical Association.

“I think there’s been a myth that all uninsured children have uninsured parents, and so if we cover the parents we can cover the kids,” said Dr. Jennifer DeVoe of Oregon Health & Science University, who led a study, in an interview. “In most cases, the parents have insurance through work at a reduced rate or no cost, but adding their family is unaffordable.”

DeVoe’s study looked at data from 2002 to 2005 released by the Agency for Health Care Research and Quality, which is part of the U.S. Department of Health and Human Services.

In 2007, 8.1 million children under the age of 18 had no health insurance, according to an August report from the U.S. Census Bureau.

The study found the majority of these children are from single parent households, Hispanic families, and are more likely to live in the South or West.

Many of these children may be qualified for public assistance, but their parents may not be aware of this fact, said Dr. Carolyn Clancy, who is head of the Agency for Health Care Research and Quality.

Click here for more on this story from Reuters.

Click here to learn more on this study published in JAMA.