Twenty-nine percent cited retirement medical expenses as a concern for them, while 39 percent said they were nervous about paying for long-term care. Both figures have risen over the last year.
Nearly seven in 10, meanwhile, expressed a lack of confidence that their future Medicare benefits would be equal in value to today's.
Researchers tied these responses to the recovering economy, a lack of retirement savings on the part of workers, and rising personal debt.
"Many [people] lack even a short-term cushion," said Matt Greenwald, who conducted and co-sponsored the report.
"Only about half of workers and a comparable number of retirees say they could definitely come up with $2,000 if an unexpected need arose within the next month."