According to a report released Wednesday, 86.7 million or one out of three Americans under 65 had no health insurance at some point during 2007 and 2008.

The report commissioned by the nonprofit consumer health advocacy group Families USA examined data from the U.S. Census Bureau's Current Population Survey and its Survey of Income and Program Participation as well as information from the Medical Expenditure Panel Survey.

On the basis of this data, Families USA reported that the number of people without health insurance is higher than levels frequently cited by the U.S. government and others. According to the U.S. Census Bureau in 2007 there were 45.7 million uninsured Americans.

The reason for this discrepancy in numbers Families USA said is as the Census bureau counts only people who were uninsured for the full calendar year. On the other hand Families USA for its own study commissioned The Lewin Group to analyze data from the Census Bureau and the Agency for Healthcare Research and Quality. Its study includes people who did not have health insurance for all or for part of the past two years.

The report found that out of the 86.7 million uninsured individuals, 60.2 % were uninsured for nine months or more, while nearly 74.5 % were uninsured for six months or more. 52 % of individuals in families with incomes between $21,200 and $42,400 per year went without health insurance at some point in 2007-08.

A fact highlighted by the report was that four out of five uninsured Americans are from working families, and with more and more workers being laid off their jobs these figures were bound to rise. They added that people without health insurance are less likely to have a usual doctor and often go without screenings or preventative care.

Ron Pollack, executive director of Families USA, in a press release said, "The huge number of people without health coverage is worse than an epidemic. Inaction on health care reform in 2009 cannot be an option for the tens of millions of people who lack or lose health coverage each year ... the cost of doing nothing is too high."

According to critics the number of uninsured Americans in the Families USA report is misleading. "No one disagrees we have a problem with the uninsured," said Douglas Holtz-Eakin who was Sen. John McCain’s advisor on domestic and economic policy during the 2008 election.

The study came out the day before President Obama who says reforming health care is one of his top priorities, is scheduled to hold a health care summit at the White House. According to Holtz-Eakin, Families USA is exaggerating the numbers to make a political point the day before the White House summit. "They are simply choosing to report over a two-year window a measure that always gives you a larger number."