An estimated five million uninsured children in the United States were eligible for Medicaid or the Children's Health Insurance Program (CHIP) but were not enrolled in either plan, according to a new report.

The study published on Friday in the journal Health Affairs recommended policy reforms and broader efforts to get uninsured children into government medical programs, including the use of income tax data for automatic enrollment.

An estimated 7.3 million children were uninsured on an average day in 2008 and 65 percent of them were eligible for Medicaid of CHIP coverage, the report said.

President Barack Obama, who signed landmark healthcare reforms into law in March, has made providing health care to all Americans a top priority of his administration.

Thirty-nine percent (1.8) million of eligible uninsured children live in just three states -- California, Texas and Florida, the report by the Washington-based Urban Institute Health Policy Center said. Sixty-one percent (2.9 million) of uninsured children live in 10 states, the report said.

This new data will help us to focus our efforts and our grant funding where they are most needed, U.S. Secretary of Health and Human Services Kathleen Sebelius said in a statement. We now have a much better sense of where most uninsured children live, and which communities may need more help.

Medicaid is the joint state-federal health plan for the poor, disabled and elderly. CHIP provides low-cost coverage for children in families who earn too much to qualify for Medicaid but cannot afford private health insurance coverage.

No child should have to skip a doctor's appointment or go without the medicine they need because their family can't pay, Sebelius said, challenging state and local officials to find and enroll those five million kids.