A large majority of baby boomers are delaying their retirement by an average of five years, according to a new study.

The study, Middle-Income Boomers, Financial Security and the New Retirement, was conducted by Bankers Life and Casualty Company Center for a Secure Retirement. It found that 73 percent of America's middle-income baby boomers are rethinking their retirement thanks to the economic crisis, and of those, nearly 8 in 10 (79 percent) are delaying their retirement by an average of five years.

Additionally, 14 percent of boomers believe they will never be able to retire due to the turbulent economy, according to the study, which focused on 500 middle-income Americans between ages 47 and 65 with incomes between $25,000 and $75,000. 

There are several factors contributing to this shift in retirement age and timing for the middle-income Baby Boom generation. According to the study, 71 percent worry about outliving their money once they retire, 68 percent have experienced a decline in the value of their retirement accounts within the past three years and 55 percent have saved less than $100,000.

Additional study findings include:

• In light of the recent decline in the economy, working in retirement is fast becoming a new reality for many middle-income Americans. The study found that 75 percent expect that their retirement will involve work in some form and more than half (57 percent) say that they will have to work for financial reasons.

• While most people expect that they'll be able to choose when they retire, two-thirds (64 percent) of survey participants are concerned about being forced to retire, most commonly due to loss of employment (44 percent) or failing health or disability (40 percent).