Baby Boomers may not be able to work as long into retirement as they believe, according to new research by the Insured Retirement Institute. Nearly two-thirds of Boomers say they are counting on employment during their retirement years as a source of income, several studies have found that half of workers leave the workforce prematurely.

"About half of retirees leave the workforce earlier than they planned because of, among other issues, health concerns or a lack of employment opportunities," IRI President and CEO Cathy Weatherford said. "As we live longer, it's becoming more commonplace to accept the idea that we have to work a few extra years. And rightfully so. But Boomers must reevaluate their plans and develop contingencies in case they cannot work as long as they intend. This evaluation requires identifying alternative sources of lifetime income."

Sixty-four percent of Baby Boomers and 70 percent of Generation Xers felt that they would continue working in retirement to gain extra income. According to the IRI data, 35 percent of Baby Boomers plan to work into their late 60s and beyond, with 12 percent of Boomers planning to work into their late 60s and another 23 percent planning to work to age 70 or older. Labor force participation rates in 2010 reveal that only 17.9 percent of those aged 65 and older were still in the workforce, according to the Bureau of Labor Statistics.