NEW YORK (CNN/Money) - About two-thirds of American workers expect to work full or part time after retiring from their main job, according to a newly conducted survey that found rising anxiety about retirement income.

The survey of 800 Americans, conducted in May and June by the John J. Heldrich Center for Workforce Development at Rutgers University, found that 66 percent expect to be doing some kind of work when they reach retirement age.

While that's down from the nearly three-quarters who expected to keep working the last time the survey was conducted in 2000, the reasons those surveyed expect to keep working has shown a significant shift.

The latest survey found that 24 percent plan to work full time or part time because they need the money, almost double the 13 percent who expected to do so in a 2000 survey.

The percent that said they intend to work part time or to pursue an interest similarly fell to 27 percent from 44 percent that expected to do so in the 2000 survey.

In addition, the survey found that 12 percent believe they'll never be able to retire, up from 7 percent that believed that in the 2000 survey.

"The traditional notion of retirement, where one stops working completely and enjoys leisure time with friends and family, is obsolete," said Carl Van Horn, director of the center and co-director of the survey project. "In fact, workers in 2005 feel less confident than they did in 2000 that they will be financially able to leave the workforce ahead of the traditional retirement age."

The survey finds a growing gap as to what workers believe is the ideal retirement age, and when they expect to have the financial resources to retire.

For example, in the most recent survey, 91 percent said they would ideally like to retire by age 65, but only 63 percent expect to retire by then. In the 2000 survey, a similar 89 percent ideally wanted to retire by age 65, but at that time 82 percent of those surveyed expected to be able to retire by then.

Part of the retirement anxiety comes from doubts about government retirement programs.

Half of current workers age 44 and younger disagree with the statement, "Social Security and Medicare will still be available to me when I retire." In addition, 40 percent of workers ages 45 to 54 also disagree with that statement.

Despite these doubts, the survey found 35 percent of current workers saving nothing to supplement their retirement income beyond Social Security benefits.

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