The percentage of older Americans who are part of the workforce has grown, driven mostly by older women who are is still working, according to a report released Wednesday by the Employee Benefit Research Institute (EBRI).

The percentage of Americans over the age of 55 who are part of the workforce had grown steadily to a high of 40.5 percent in 2012 before dipping slightly to 40.3 percent last year, EBRI says in the study, Labor-force Participation Rates of the Population Ages 55 and Older, 2013.

Prior to 1993, when it reached a low of 29.4 percent, the percentage of older Americans in the workforce had been declining, according to EBRI, which used U.S. Census Bureau data for the calculations.

“The upward trend in labor-force participation by older workers is likely related to workers’ current need for continued access to employment-based health insurance and for more years of earnings to accumulate savings in defined contribution plans and/or to pay down debt,” says Craig Copeland, senior research associate at EBRI and author of the report. “Many Americans also want to work longer, especially those with more education for whom more meaningful jobs are available that can be performed into older ages.”

Copeland also noted that younger workers’ labor-force participation rates increased when that of older workers declined or remained low during the late 1970s to the early 1990s. However, as younger workers’ rates began to decline in the late 1990s, those for older workers increased.

“It appears either that older workers filled the void left by younger workers’ lower participation, or that higher older-worker participation limited the opportunities for younger workers or discouraged them from participating in the labor force,” he adds.

Women who continued to work were the cause of the increased participation in the labor force for older Americans, the data shows. Female labor-force participation rates for 55 to 60 year olds from 1975 to 2013 increased sharply, despite some leveling off in the last four years. The 1975 rate for those females was 47.9 percent, compared with 67.2 percent in 2013.

By comparison, the percentage of older men in the workforce declined slightly between 1975 and 2013 from 49.4 percent to 46.5 percent.

The full report can be found in the April EBRI Notes at