"A traditional measure of quality of health care is whether children get the key immunizations that are recommended for young children," Schor said.
Artman and researchers alike also touted the importance of a "medical home," also described as a primary care provider that families can go to as needed with their questions or concerns. Only one-third of children in Mississippi have a medical home, which contributed to the state's ranking as No. 49 overall. That's dramatically different from the 61 percent of children in New Hampshire who have a medical home they can access regularly.
"Health care and particularly child health care rests on the relationship between the family and the health care provider," Schor said.
Oklahoma ranked lowest on the Commonwealth Fund's list for children's health care. Florida, Mississippi, Louisiana and Arizona also took places at the bottom of the ranks.
Arizona, Louisiana, Mississippi also ranked close to the bottom when it came to access to care.
Across most states, minority, low-income and uninsured children received lower quality care. The rate of children who are uninsured ranged from 5 percent in Michigan to 20 percent in Texas.
Among Southern states, Alabama stood out as an exception to the trend, ranking 14th overall for kids' health care.
"Certainly with regard to Alabama, it was a matter of leadership," Davis said. "The state was the first one to take advantage of the state child health care program in 1997. It was also very efficient at forging a public-private partnership specifically with Blue Cross Blue Shield of Alabama."
To improve health care for children, the Commonwealth Fund recommended reauthorizing the State Children's Health Insurance Program, known as SCHIP, a federal program that aims to help states cover uninsured children in low-income families. Researchers attributed Iowa and Vermont's success in large part to that program and to the states' requirements for health plans and children's health care systems to report data on SCHIP.
Six million children nationwide are covered by SCHIP, and 28 million children nationwide are covered by Medicaid, meaning that more than one-third of children around the country get health care that's funded by the federal government as well as by the states.
President Bush and Democratic lawmakers in Congress butted heads over the details of reauthorizing SCHIP in 2007 and were forced to extend the program as is until next year.