BOSTON (MarketWatch) -- We all think it’s a panacea. If you don’t have enough money saved for retirement, you’ve got a few ways to close the gap between what you have and what you need in your nest egg: Save more, invest more aggressively, and/or work longer.

Well, it turns out that working longer is indeed an option, according to the Employee Benefit Research Institute latest study. The only problem is that the latest research shows that you’ll have to work much longer than you anticipated. In fact, many Americans will have to keep on working well into their 70s and 80s to afford retirement, according to the study, titled “The Impact of Deferring Retirement Age on Retirement Income Adequacy.”

What’s more, it’s even worse for low-income workers, according Jack VanDerhei, one of the co-authors of the study. Those who earned (on average over the course of their careers) less than $11,700 per year, the lowest income quartile, would need to defer retirement till age 84 before 90% of those households would have just a 50% chance of affording retirement.

Those who earned between $11,700 and $31,200 will need to work till age 76 to have a 50% chance of covering basic expenses in retirement. Those who earned between $31,200 and $72,500 will need to work to age 72 to have a 50% chance and those who earned more than $72,500, those in the highest income quartile, catch a break; they get stop working at age 65 to have a 50/50 chance of funding their retirement.

So what can be done to make sure you have enough income in retirement? Well, the sad truth is that not working is no longer an option and working past age 65 is fast becoming a fact of life, at least for those in the lowest three income quartiles.

One bright spot, according to John Nelson, co-author of ‘What Color is Your Parachute? For Retirement’ is that working works: “For those in the lower half of the income spectrum, delaying retirement from 65 to 69 has a profound effect,” he said. “It increases retirement income adequacy by 25% to 50%! That’s a powerful incentive.”

The new normal

Now the reality about EBRI’s findings is that many Americans — who are able to continue working and whose skills are still in demand — are already working past age 65. In 2009, 17.2% of Americans age 65 and older were in the labor force, according to recent AARP Public Policy Institute report, “Family Income Sources for Older People, 2009.”

And about 14.2 million older persons (36.7% of the older population) had family incomes from earnings in 2009. The median family income from this source was $32,330, while the mean was nearly 1.6 times as large — $50,971. Read the AARP report here.

And the new normal isn’t that people are working past age 65, rather it’s this: They are also hunting for second jobs as all, according to Art Koff, founder of RetiredBrains.com. “Even those older Americans who are still working are looking for ways to make additional monies,” he said.

And many, judging from the page views at RetiredBrains.com’s website, are often exploring ways to work from home. “Those older Americans who are looking for a job, those who have already retired and those who are working but need additional income or want to start something that they can continue into their retirement years are all reading (the work-from-home) pages,” Koff said.

Making it work

To be sure, many Americans haven’t figured out how to make working later a real option, instead of just a fantasy. And for them, Nelson has this advice: “You need to pay attention to your career and your health.”

“First, for your career, do some in-depth research and planning. Second, for your body, take a health risk assessment. You may need to keep both of them in shape longer than you thought,” he said.

Work and save

Working past age 65 is certainly one way to make sure you have enough income to fund retirement expenses. But EBRI also noted that Americans who work past age 65 who continue to save for retirement in a 401(k) or some such account earmarked for retirement increase the odds of having enough income in their golden years. “One of the factors that makes a major difference in the percentage of households satisfying the retirement income adequacy thresholds at any retirement age is whether the worker is still participating in a defined contribution plan after age 65,” the co-authors of the report. “This factor results in at least a 10 percentage point difference in the majority of the retirement age/income combinations investigated.” The EBRI report can be found at this website.

A new compact

Others, meanwhile, have a different take on EBRI’s study and findings. “This report just reinforces the need for a new social compact that provides increased financial security in return for increased contribution,” said Marc Freedman, author of “The Big Shift: Navigating the New Stage Beyond Midlife and CEO of Civic Ventures.”

“We need to enable the many people who want and need to work longer, without hurting those who are not able to,” Freedman said.