WASHINGTON - The quality of health care Americans receive depends largely on where they live, with insurance coverage, access to preventive medicine and disease treatment varying widely from state to state, according to a study released on Thursday by the Commonwealth Fund.

"Where you live matters," said the foundation's Vice President Cathy Schoen, who co-authored the study for the private research group, in a conference call with reporters. "And it shouldn't."

The report found that all of the states that have made health care reforms provide better access to medical treatment and prevention and mostly avoid costly hospital procedures.

Residents of Vermont have the best health care in the country, the foundation said. The small northern state, which embarked on a radical plan to provide all citizens with health care less than a decade ago, also leads the nation in "equity," or making sure that people of lower income groups have health care.

The report comes as the U.S. Congress inches closer to finalizing a plan to reshape health care. So far, drafts of the plan have emphasized relying on the states to operate insurance exchanges and possibly to extend more health insurance to families with lower incomes.

"The patterns indicate that public policies, plus state and local health care systems, can make a difference," according to the report, which was also conducted by Joel Cantor, director of the Center for State Health Policy at Rutgers University.