Many senior citizens are still in the labor force.

About 78% of Americans ages 55 to 59 are working or looking for work, according to results of a survey commissioned by a unit of MetLife Inc., New York.

Although the percentage falls to 60% for the 60-65 age group and 37% for the 66 to 70 age group, the results show that a large minority of older Americans are not fully retired.

Across all 3 age groups studied, about 15% of workers have accepted retirement benefits from previous employers and then returned to work or set about looking for work, MetLife researchers report. The percentage of individuals who fit in the “working retired” category rises to 19% in the 66-70% age group, from 11% in the 55-59 age group.

The study, conducted by David DeLong & Associates Inc. and Zogby International found older workers struggling to balance the weight of income security and post-retirement-age employment to achieve security and meaning during a time in their life generally thought of as retirement years.

Workers in the 55-59 age category were more likely than other older workers to say that they are still working because they need the money.

Workers in the age 66-70 category were more likely to cite a desire to stay active as the primary reason to work.