The US healthcare system is plagued by inefficiency, inequality and an incoherent national policy, said the report from the private Commonwealth Fund foundation.
"The US spends twice per capita what other major industrialized countries spend on health care, and costs continue to rise faster than income," said the report.
"We should expect a better return on this investment."
The foundation used a 100-point scorecard to rate the system based on 37 categories, including access to health care, quality of care and efficiency.
The US average came to 65, two points down from a previous measure in 2006. The score is compared to other countries and the best performing US states, counties or hospitals.
The measures showed "that the US is losing ground in providing access to care and has uneven health care quality" and also revealed "broad evidence of inefficient and inequitable care," it said.
The United States ranked last among 19 industrialized states when it comes to preventing premature deaths from conditions such as heart attacks that can be treated with timely, effective care, the report said.
Up to 101,000 less people would die prematurely if the US achieved the lower mortality rates of top performing countries such as France or Japan, it said.
Infant mortality rates also remain high in the United States compared to other industrialized nations.
Access to health care was on the decline, with more Americans without health insurance or without adequate insurance. In 2007, 75 million working-age adults were either uninsured or underinsured, up from 61 million in 2003.
Americans reported more delays in securing appointments with doctors. "In 2007, as in 2005, less than half of US adults with health problems were able to get a rapid appointment with a physician when they were sick," it said.
The US scored poorly on efficiency, with patients subjected to duplicate tests, unnecessary hospital admissions, high administrative costs and outdated record keeping, it said.
Only 28 percent of US doctors use electronic medical records, compared to nearly 100 percent in leading countries.
The report, based on data from US government agencies and other sources, underlined some areas of progress, including improved safety at hospitals and better control of diabetes and high blood pressure.