Most U.S. workers expect to work for at least a year after they reach age 67 for financial reasons.

Researchers at the Wellesley Hills, Mass.-based U.S. division of Sun Life Financial Inc., Toronto, have published that finding in a summary of results from the company’s latest “unretirement survey,” which was conducted in early December 2008.

Sun Life began sponsoring the quarterly survey series in August 2008.

An interviewing firm gets the survey responses by making enough calls to come up with a sample of 1,200 U.S. workers ages 30 and older.

Sun Life developed the survey series to look into “unretirement,” or the practice of working at least 20 hours per week after an individual is eligible to receive Social Security benefits.

About 54% of U.S. workers expect to continue employment for at least a year after reaching the normal retirement age, and 24% expect to work for 5 years or more after reaching the normal retirement age, researchers report.

Those figures were about the same in December as they were in August, but the percentage saying they would continue working for financial reasons, rather than for nonfinancial reasons, increased, the researchers report.

The top reason, cited by 83%, was “to earn enough money to live well,” and the second-most-cited reason, named by 80%, was “to stay mentally engaged.”

About 64% said they would continue working “for the health care benefits.”

Workers ages 40-49 were most likely to say they would be unretired to get health care benefits.

Researchers also found that 67% of participants said they are reducing their spending, and 55% said they are reducing their debt.