Washington ? Nearly three out of five middle-class retirees will probably run out of money if they maintain their pre-retirement lifestyles, a new study from Ernst & Young has concluded.

The study, set to be released today, finds that Americans will have to drastically reduce their standard of living before retirement to live comfortably, or even avoid destitution, later in life. Middle-income Americans entering retirement now will have to reduce their standard of living by an average of 24 percent to minimize their chances of outliving their financial assets, the study found. Workers seven years from retirement will have to cut their spending by even more – 37 percent.

“People are going to have to adapt in a number of ways that they weren’t anticipating or hoping for,” said Tom Neubig, national director of the Quantitative Economics and Statistics practice at Ernst & Young. “I think a lot of people are hoping to maintain roughly the same standard of living after retirement. Our study suggests they are going to have to make some changes.”

About 77 million baby boomers are expected to retire over the next few years. The study warns of an impending national crisis if workers, and lawmakers, do not react now to the changing pension structures in corporate America. Most companies have moved away from defined-benefit plans, in which they provided their retirees with a set benefit each month, to defined-contribution plans such as 401(k)s, in which the employee takes most of the responsibility for saving money. But with the U.S. savings rate abysmally low and people underestimating their life spans, economists warn that aspiring retirees will have to work longer if they do not spend less, no small feat at a time when inflation and the cost of living are rising. Fluctuating investment returns on 401(k)-style plans in this wobbly stock market are not helping matters.

“Most people, if they look at their life expectancy and they think they will live to 90, they are nuts to retire at 60. They’re going to be living in poverty at 80,” said Peter Morici, an economist at the University of Maryland. “I think it’s a wake-up call to baby boomers to get serious about getting their houses in order.”

The study was commissioned by Americans for Secure Retirement, a coalition of more than 50 organizations representing women’s, small business, agricultural, Hispanic and African-American groups, among others.