DES MOINES, Iowa--It could be a major problem. Workers in their 20s and 30s using their retirement funds to pay credit card debt and home mortgages instead of leaving it alone to accumulate.

Fidelity Investments released a survey Thursday that said large numbers of young workers cash out their 401(k) accounts when they switch jobs, leaving them without an accumulation of cash for retirement.

"The typical Gen X or Gen Y will work for seven different employers across their career," said Scott David, president of retirement services for Boston-based Fidelity Investments. "If you consider the combination of the withdrawal behavior with that propensity for multiple employers, I do think we are facing a savings challenge and crisis with this generation."

Generation X workers, those born between 1967 and 1975, said money is their top concern with 77% of them saying it's their biggest worry. About 74% of generation Y workers, born between 1976 and 1987, said money worried them most.

Half of the workers in the two age groups said saving for retirement is an obligation or a goal but 51% said other financial priorities prevent them from setting aside money. Mortgage payments and managing credit card debt ranked higher in importance than retirement saving.

"Our research revealed that younger generations are more likely to use credit than save for short-term purchases, which results in an ongoing struggle with debt management," said Pam Norley, executive vice president with Fidelity Consulting Group. "There's a real instant gratification approach that they have and I'm not sure it just goes with age. We're seeing even in the folks in their early 30s, they actually have workplace savings and change jobs then use it for other purposes."

Nearly 60% of both age groups said they didn't believe they were making solid financial decisions yet 41% said they didn't seek financial advice when changing jobs. Of this group, 56% cashed out their work place savings plans.

David said the key to changing the behavior is to get younger workers to seek advice when they change jobs so they understand they can leave the money with the employer, roll it over to the new employer's plan or put the money in an IRA.

"It's surprising how many people just don't understand their options at termination," he said.

He said financial education should be offered at the high school and college levels.

Fidelity and Atlanta-based research company CMI conducted multiple personal interviews with 40 people in four cities and then surveyed 1,200 adults aged 20 to 40. The research was done between October 2007 and January 2008. The survey statistical margin of error is plus or minus 5%.

The U.S. Bureau of Labor Statistics says Generation X and Generation Y workers will surpass baby boomers as the largest single segment of workers in the United States by 2010 when they will represent 60% of the U.S. work force.

Boston-based Fidelity Investments is a leading provider of work place retirement savings plans, mutual funds and other financial services. It had $1.5 trillion in managed assets as of July 31.