Millions of college graduates who saw a degree as their ticket to a good-paying career and a secure life are working in jobs that do not require their education or even a high school diploma, sometimes leaving them with small wages to pay thousands in student loan debt, according to a new study.

About 48 percent of all working college alumni — not just recent graduates — were underemployed in 2010 as the United States began a slow recovery from the Great Recession, including 5 million graduates in jobs that require less than a high school diploma, according to a study from the Center for College Affordability and Productivity.

“The economy may be in recovery officially, but there are a lot of people who haven’t recovered yet,” said Jonathan Robe, one of three researchers on the report, “Why Are Recent College Graduates Underemployed.” “This is a problem that’s sticking around.”

When so many graduates are working in retail sales and as bartenders, janitors and maids, the study calls into question the appropriateness of extra spending to reach broad goals for more Americans to earn college degrees. President Barack Obama has charged that the United States lead the world in degree holders with 10 million more graduates by 2020. It also suggests that the underemployment problem is not going away because there is a growing disconnect between what employers need and the volume and nature of the training of college students.

Still, others say the data is looking back to the effects of one of the worst recessions America has ever seen. The Georgetown University Center on Education and the Workforce forecasts that 63 percent of all jobs will require some postsecondary education by 2018 — and the U.S. is on track to fall short of that need by 3 million workers.

“You’ve got to look to the future,” said David Hopkins, president of Wright State University in Dayton, Ohio. “In the next decade, they anticipate 31 million jobs being produced in the country that require education beyond high school.”

Underemployment has left some college graduates struggling to pay their student loans, working multiple jobs to make ends meet, and facing the possibility of life without health insurance — and little hope things will change soon.

Jessica Stringfield, who graduated from Miami University in 2011 with a degree in journalism and political science, has until March to find a job offering health insurance to pay for her insulin before she turns 26 and is no longer eligible to be on her mother’s health care plan. With four recent interviews and no job offers, she said the search is scary.

“I know I have a flawless resume, amazing letters of recommendation, a wonderful college degree and perfect interview skills, so it’s a very perplexing, discouraging situation to be in,” said Stringfield, who now works as an administrative assistant for a small dance studio that doesn’t offer her benefits. “Without insurance, my medication runs over $1,000 a month. There is no possible way I can afford that.”

Ohio University graduate Joe Brotherton, 25, had a job lined up at a law firm when he graduated with a political science degree in 2009. But so close to the economy’s collapse, the firm had to cut back and told him, “Luckily, you’re not losing a job; you’re just not going to get it.”