It’s a nice image – a slice of Americana, like a Norman Rockwell painting. But, like many of the idealized images in those paintings, the concept of “traditional retirement” at a pre-determined age is rapidly becoming a thing of the past.

Fast forward to the new millennium. Professional men – and women – are living longer, and also working longer. Defined-benefit pensions have largely been replaced by defined-contribution 401(k) plans. Some employees feel they have to work longer, as their retirement savings are inadequate or have been partly allocated to pay for their healthcare.

Others want to keep working, or embark on a second career that diverges from what they did for most of their professional lives. The bottom line is that age 65 is now just a number along a continuum, and no longer the official onset of retirement for many Americans.

Should It Be Called 'Retirement?'

There’s no shortage of statistics to indicate the presence of older employees in the workforce, at least on a part-time basis. A new survey of U.S. workers found that 82% of respondents age 60 or older expect to work past 65. That's according to a recent article from USA Today. Among all people canvassed, 20% said they expect to keep working as long as possible.

The president of the Transamerica Center for Retirement Studies, which conducted the study, says it represents “a call to action… to really revisit basic workforce management principles.” She also offers a reminder that many Americans who now opt to work for more than the traditional 20 or 30 years are also consumers and still very much a vital part of the nation’s economy.

The study indicates that 44% of respondents cited outliving their savings and investments as their top retirement concern, while a third of those surveyed expect their standard of living to decline once they stop working. The retirement center president, Catherine Collinson, is concerned most about the 40-something members of Generation X, many of whom, in addition to being hit hard by the Great Recession, find themselves “sandwiched” among their careers, raising children and caring for aging parents.

While this population still has time to plan for their retirement years, only 10% of the survey respondents in this age group expect to be able to fully afford a comfortable retirement. The findings make Collinson wonder whether “retirement” is still a term that even applies to Americans in their later years.

More Volunteers Than Victims

Ask a different study, get different results. A new one conducted by Merrill Lynch in conjunction with AgeWave, a special interest group dedicated to the aging population, finds that some 72% of workers nearing retirement age actually want to keep on working (see Fox Business blog below). The survey authors conclude that there are now four different types of retirees – a finding that effectively redefines how we think of retirement in the 21st century:

• Driven Achievers - The smallest percentage of respondents (15%), these tend to be successful professionals who are still at the top of their game and see no reason to stop working.
• Caring Contributors - This sector, roughly a third of the working retired, wants to “give back” in their later years and is more focused on the type of work they do rather than the money.
• Life Balancers - While this group (about 25%) may need the income or seek the social interaction of the workplace, they’re looking for more of a “balance” in their lives, and can be somewhat flexible about their schedules and the type of work they choose to do.
• Earnest Earners - This segment (28%) needs to work but would rather be retired, given their druthers.

The survey also found that more and more retirees are taking steps to avoid falling into the last category above as they approach traditional retirement age. Workers in the pre-retirement stage were found to have done some financial planning within five years of retiring (37%), with a larger percentage (54%) doing so within two years of stopping work.

A Mixed Bag for Employers

Still, not everyone is thrilled with the trend toward more working 'retirees', including some in the workforce who feel displaced by older workers, as well as employers faced with increasing costs incurred by aging employees. The findings of yet another comprehensive survey, of more than 4,000 full-time U.S. workers conducted recently by employment consultants TowersWatson, are somewhat more pessimistic.

This study reveals a perception that older workers are “clogging” the job market and impeding job “opportunities for the young.” That's according to a recent article from MarketWatch. Further, it strikes a note of caution for employers: that older workers tend to be more stressed, less healthy and more “disengaged” from their jobs than younger employees. The result, according to TowersWatson: a productivity drag for employers.

The study cites an inverse in traditional labor participation rates for American men in the past 25 years: while they’re fallen for 25-54 year-old males by about 5%, they’ve risen sharply for men 65 or older (by about 7%), with a growing number of pre-retirees in the 55-64 age range either employed or looking for work. Fingers point to the change in how retirement benefits are structured at companies, but also to Social Security, where the so-called “full retirement age” has risen from 65 to 67 for much of the Baby Boom population.

While this survey, like the others discussed earlier, finds sharply upward trends in retirement age and the number of working retirees, it also reveals something of a quandary for employers. On the one hand, they have the benefit of keeping knowledgeable and experienced workers on staff for longer periods of time. On the other hand, older workers do indeed incur higher healthcare costs, and may in fact be somewhat less productive than their younger counterparts.

Concurrently, companies may have to slow down their recruiting and hiring of the next generation of staffers they will eventually need to replace the older employees.

So where does this leave the work force and employers in 2015? In a state of flux, like most other aspects of the global economy and of corporate America. Baby Boomers and Gen X’ers can’t afford to retire as easily as their parents did, so are planning longer working lives. Millenials are on the rise in the workplace, but will face new challenges as they plot their career paths.

The assembly-line jobs of the late 20th century are giving way to robotics and a knowledge- and technology-based economy. That means older people can work longer, work remotely, work differently than ever before. It means that companies will need to adapt to changing demographics and an aging population.

Perhaps, in an ironic twist, it may even force employers to revisit the way they structure retirement benefits – even at the expense of healthcare, bonuses or vacation pay. Otherwise, they may find themselves before mid-century with a significant geriatric population on their payrolls.