Of the 43 million working-age adults who lost jobs during the recession in the past two years, about nine million, or 20 percent, ended up without insurance, according to a new study.

The nine million left without insurance represented 57 percent of all those who lost insurance when they lost their job, according to the biennial study by The Commonwealth Fund, a healthcare research and reform advocacy group.

Twenty-five percent of people who lost employer-sponsored health insurance were able to find another source of health insurance coverage, while 14 percent continued their job-based coverage through COBRA

But purchasing individual coverage turned out to not be a viable option for many. The study found that an estimated 26 million adults bought, or tried to buy, health insurance on the individual insurance market in the past three years but 16 million of them found it very difficult or impossible to find a plan they could afford. An estimated nine million said they were turned down or charged a higher price because of a health problem, or had a preexisting condition excluded from their coverage.

According to the survey, an estimated 52 million American adults were uninsured at some point during 2010, compared to 38 million in 2001. Adults in families with low and moderate incomes were the most likely to be uninsured; 54 percent of lower-income adults (under $22,050 for a family of four) and 41 percent of moderate-income adults ($22,050 to $44,100 for a family of four) were uninsured for some time during the year, compared with 13 percent of adults with higher incomes.

According to the survey, 73 million people reported problems paying their medical bills or were paying off medical debt and quarter of adults with chronic conditions who took medications skipped their medications or didn’t fill a prescription because of cost.

“The survey shows that over the last decade, increasing numbers of people across the income spectrum went without health insurance, avoided timely health care because it was too expensive, and struggled with medical debt,” said Sara Collins, Commonwealth Fund vice president and study author. “Millions of working families reported making difficult trade-offs between paying off their medical debt, buying other life necessities, and saving for the future.”

She said the federal health reform signed into law by President Barack Obama will help “ensure that families will have the financial means to get the health care that they need, both in good economic times and bad.”

That law aims to expand health insurance to more than 30 million people. Some provisions of the new law including one allowing young adults to stay on their parents’ policies have gone into effect but most of its requirements including insurance exchanges for purchasing health plans do not go into effect until 2014.

The law has come under fire from Republicans as hurting job growth and it is being challenged in the courts as unconstitutional. The legal challenges are expected to eventually reach the U.S. Supreme Court.