Across the nation, millions of older active Americans are retiring old notions of what it means to be retired.

They are America's New Retirees, a growing army of people who are using their later years to rethink and revitalize their lives. They are reinventing retirement—trying new careers, launching new businesses, volunteering eagerly, returning to school and pursuing other paths that build on the interests, skills and wisdom they've acquired through the years.

Their mounting numbers form the vanguard of what Helen Dennis, a retirement expert at the University of Southern California, calls "a retirement revolution."

Thirty years ago, says Dennis, retirees "may have been looking for more of a rest. Today's group is saying, 'Give me a little rest, but I'm ready for the next challenge.' "

The trend emerges clearly from statistics that show more older Americans are working, volunteering and going back to school than ever before. And it's seen in countless examples of older people striking out in new directions.

To explore the trend, the AARP Bulletin talked to dozens of experts and New Retirees alike. The chief finding: "Ordinary" people are today doing some extraordinary things in their later years.

Take Bob Rosier, 56, of Charleston, W. Va., who retired from state government and now combines part-time work as an office manager with full-time devotion to creating stained-glass artworks.

Or sisters Barbara Barasch, 53, and Arlene Lyons, 56, who retired from city jobs in California and Texas to buy and run a cafe in Ten Sleep, Wyo. (population 304).

Or Linda and Fred Gralenski, 57 and 65, of Pembroke, Maine, who find themselves so involved in volunteer work that Linda says having a full-time job might have been easier.

The new activism has muddied the very terminology of retirement. When asked, for example, if he's retired, Bob Rosier answers with hesitation: "Yes and no—I don't know, I'm confused."

Experts say that the revolution is fueled by the fact that today's 50-plus population is generally healthier and wealthier than its forebears and has many more opportunities open to it. And they say that work—both paid and unpaid—is at the center of this trend.

Some 18 million men and women 55 and older are still in the work force, and a recent AARP survey suggests the numbers will continue to grow.

The survey found that seven out of 10 workers 45 and older plan to work during their retirement years. While earning money is a major motivator, one in three say they will work mainly for enjoyment and a sense of purpose. They want greater flexibility and autonomy, however, in their working conditions.

Joseph F. Quinn, dean and economics professor at Boston College, says longer life is driving the trend. "People are saying, 'I've got a couple of decades of potentially productive life ahead of me,' " he says. "Many are deciding that some combination of less work and more leisure for a while is preferable to staying on full time at a career job or complete labor force withdrawal."

Although most people still retire "in one fell swoop," Quinn says, about a third to a half of all retirees work at "bridge jobs" before they opt for retirement.

Older people constitute the backbone of American volunteerism, working not for money but to help others. In fact, experts say if it were not for the 28 million volunteers 55 and older—about half the national total—the volunteer sector would almost come to a halt.

The Gralenskis of Maine, for example, are serving their community by comforting the terminally ill with hospice care, converting a historic building into their town's first public library and helping at a local food pantry.

They and many other New Retirees have concluded that having a mission can make a big difference in life. They seek what Deborah Russell, AARP manager of economic security and work, calls "food for the soul" and what Helen Dennis of USC terms "meaningful aging."

As Wyoming cafe co-owner Barbara Barasch says, "It's healthier at any age to have a purpose."

Pete Wegner, 58, of Indianapolis, found purpose by retiring to care for his parents, now both deceased. The former owner of a Chicago drapery store served his ailing parents for seven years.

Nowadays Wegner parlays his favorite pastime into help for community causes: He takes people fishing on Lake Michigan and donates the proceeds to charities.

Bob and Joan Phillips of Homer, Alaska, 63 and 60, retired two years ago to begin touring America in a recreational vehicle. Along the way they have visited their eight sons and done odd jobs to help pay expenses, since neither has a pension.

Their real calling, though, is bringing the joy of puppet shows to children in hospitals and orphanages in various parts of the world. To date, the Phillipses have established ongoing puppet troupes in Bulgaria, Egypt, Mexico, Poland and Romania.

"We decided that if we ever do end up in rocking chairs, our memories won't be, 'Did we have beautiful knickknacks?' " says Joan Phillips. "We'll remember the places we went and the people we met."

Inspiring as such stories are, experts stress that not everyone is free to pursue their dreams in retirement. They note that many people are forced into retirement by poor health—either their own or a loved one's. And for many others, continuing to work is not an option but a financial necessity.

Sara Rix, senior policy adviser at AARP, says the recent trend among employers away from traditional pension plans and toward 401(k) plans seems to keep many older people on the job longer.

While 401(k)s may be better suited to a mobile work force than traditional pensions, they have shifted more risk to the worker, she says—a fact that's become painfully clear during the current stock market decline. As millions of older people have seen their retirement savings shrink, more have concluded they'll have to work longer in order not to outlive their savings.

Indeed, the Center for Retirement Research at Boston College reported a 2 percent jump in labor force participation among older workers this year—and said shrinking retirement accounts were to blame.

Combine these factors with a decline in employer-sponsored retiree health benefits and the rising retirement age for Social Security benefits, and "it adds up to a lot of incentive to work longer," says Dallas Salisbury, president of the Employee Benefit Research Institute in Washington.

But finding and keeping a job is not always easy for older workers. In fact, age discrimination complaints filed with the Equal Employment Opportunity Commission rose from about 14,000 in 1999 to more than 17,000 in 2001, a jump of 23 percent.

John Rock, 69, can relate to that. After 39 years in the computer industry, he retired in 1999, expecting to find another high-tech job. But younger executives kept telling him he was "overqualified."

Today the resilient Rock runs his own house-painting business in Los Angeles and looks at the bright side: The new work keeps him physically fit and less stressed. When a house is finished, he says, "I have the satisfaction that it looks real nice."

Experts say that every retirement is unique and that finances, health, family and personal preferences all help shape a person's later years.

It was, for example, a medical crisis that led Judy and Jarvis Hunt, 65 and 69, of Orleans, Mass., to quit their careers in education earlier than planned and start a bed-and-breakfast on Cape Cod. Today, they say, their health is fine, but the crisis reminded them that "life is short."

In some cases, mixed motives drive the New Retirees. Jim Clark, 68, of Millwood, Va., and his late wife, Mildred, launched a magazine in 1992 to help build support for the National Wildlife Refuge System. Before she died five years later, he promised her he would carry on. Today, Clark says, that commitment and his need for meaningful work keep him going.

There's no doubt, experts say, that "retirement work" will continue to grow in coming decades. As the boomer generation retires, its legions—76 million strong—will strengthen the trend.

"Boomers could find themselves in far greater demand—and with many more options—than the typical older worker of today," AARP's Rix says.

Arlene Lyons, who runs the Wyoming cafe with her sister, sees that as an enormous opportunity.

"The baby boomers have a huge responsibility to this country," she says. "As the healthiest and most educated generation ever, we have a real responsibility to continue contributing to this society and not become a burden on it."

People of her generation, Lyons says, "need to look into their hearts and find the things that provide them with a sense of joy and passion and explore those to the nth degree."