More than 45,000 Sacramento County residents joined the ranks of the medically uninsured in the past two years, according to a new report that further illustrates the staggering depth of the recession: a surge of 2 million Californians without health insurance.

One in four Californians, or 8.2 million people, now lack coverage, according to UCLA researchers.

The study, released Tuesday, quickly became a talking point in the national debate over health care legislation, which could culminate later this week in a dramatic up-or-down vote on Capitol Hill.

California’s newly uninsured include 400,000 children. In all, 1.5 million children in California have no health insurance, the study says.

“Given the economic conditions, we knew something was going to change, because 2009 was a terrible year,” said Shana Alex Lavarreda, director of health insurance studies at UCLA and the lead author of the report.

“We didn’t think it was going to be this huge. The numbers startled us. This is the biggest jump we’ve seen in decades.”

The UCLA study is the latest to document the country’s growing uninsured population.

On Monday, the Robert Wood Johnson Foundation estimated that as many as 59.7 million Americans could be uninsured in five years – and perhaps as many as 67.6 million by 2020 if policymakers don’t take action to contain health care costs.

The UCLA study based its findings on an update of the 2007 California Health Interview Survey using 2009 enrollee data from state agencies and insurance companies.

In 2007, there were an estimated 162,000 Sacramento County residents without health insurance – about 13 percent of the population. By 2009, that number had jumped by 46,000 to 208,000, according to an analysis Lavarreda performed Tuesday on behalf of The Bee.

The region’s concentration of government jobs cushioned Sacramento from some of the more dramatic losses found in Los Angeles and other parts of the Central Valley, the researchers said.

Between December 2007 and December 2009, the California economy shed nearly 1.4 million jobs.

As people lost jobs, they also lost health insurance through their employers – despite federal stimulus money that provided deep subsidies for COBRA payments to help them keep their employer-based health coverage. Many took the offer, but substantial numbers of the laid-off workers apparently did not.

“Even with that subsidy, we still saw this big drop,” Lavarreda said. “Without the stimulus it would have been much worse. I’d be skeptical that when the economy improves, that health insurance coverage will magically come back.”

What’s more, the price of policies bought in the individual market has escalated dramatically, prompting more people to drop coverage.

Health care advocates seized on the new data to argue for passage of a health care reform package they hope will expand access to health insurance.

“Once again, California gets to be Exhibit A on why we desperately need health care reform,” said Anthony Wright, executive director of Health Access California.

“To see 2 million people lose coverage in such a short amount of time is shocking,” Wright said.

The state’s budget troubles could mean more than $3 billion in cuts to health programs, including the elimination of the Healthy Families program, which provides health coverage to nearly 900,000 California children.

“Some of the proposals on the table now would be really disastrous,” said Wilma Chan, a former state legislator and now vice president of Children Now, an Oakland-based advocacy group.

The UCLA study concludes there are now 1.5 million uninsured children in California, up from 1.1 million in 2007.

Two years ago, an estimated 30,000 uninsured children lived in Sacramento, El Dorado, Yuba, Placer and Colusa counties, according to earlier UCLA studies. Sacramento County alone had 16,000 uninsured children.

That number has likely risen since the economic downturn, said Jennifer Kwan, program manager for Sacramento’s Cover the Kids.

“When I saw the data, it was pretty shocking to see that so many children were newly uninsured,” Kwan said.

Fewer than half of the state’s children now get health coverage from their parents’ jobs, according to the UCLA study.

“Given the number of families that have been losing employment, it’s expected that a huge number of kids would lose coverage,” said Suzie Shupe, executive director of California Children’s Health Initiatives.