If America is a land of second acts, then baby boomers are writing the script — one character, one scene at a time.

The impact on society from the sheer numbers of those born between 1946 and 1964 is unprecedented, observed Mark Mather, vice president at the Population Reference Bureau, a Washington, D.C.-based research institute.

"They've kind of disrupted everything that we're seeing," he said. Better educated and healthier than earlier generations, boomers not only are living longer, increasing demands on everything from housing to health care, they also are working longer, changing the way people think about career and retirement, he said.

David Alley is executive director at Shift, a Twin Cities-based organization that runs programs focused on navigating midlife work-life transitions. Shift's mission, he says, is helping participants combine "purpose, passion and a paycheck" in what he describes as "the perfect trifecta." And those seekers have a lot of company: Nearly 19 percent of people 65 and older remain in the workforce, a number that has been steadily growing since the mid-1980s and stands at the highest level in half a century, according to the Bureau of Labor Statistics.

Three Shift alumni shared with me their very individual stories about writing their own second acts.

Charting a phased retirement

While no longer working for pay after a 37-year career spent mostly at Medtronic, Ron Stuedemann, like many retirees, keeps busy in volunteer activities including roles on the boards of both Shift and a Medtronic retiree group. But to get there Stuedemann created his own unique path to retirement.

As he approached his 61st birthday a decade ago, ("the same age my dad died," he recalls) Stuedemann wondered how he would decelerate from the fast pace he was used to as manager of global customer support and hand off his highly technical job at the global medical device maker. He proposed phasing himself out over the following year while helping identify and mentor successors. He also cut back to four days a week while exploring life outside of work, taking a 20 percent pay cut.

As more boomers retire from specialized jobs with a thin bench of experienced replacements behind them, phased retirement is an obvious solution, Stuedemann believes, because it simultaneously fosters career growth for younger workers. But most companies lack formal policies on phased retirement, and late-career employees may fear that suggesting it will marginalize them, he said.

While Medtronic had no precedent for his script, his manager agreed to it "because it made business sense. It was right for the functions, right for the people," Stuedemann noted.

Building a portfolio career

After his second layoff in 1998 following a 30-year career with city and regional planning agencies in Texas and Minnesota, Vic Ward vowed never to work in a big organization again. He taught himself how to build websites and launched his first of many business start-ups.

Today, the 71-year-old provides research on future careers to the Minnesota State Colleges and Universities (MnSCU) website. After participating in a Shift workshop, he also launched a training program teaching seniors how to use smartphones and tablets. And now he is rewriting that same Shift curriculum to help other boomers find satisfying work or volunteer opportunities.

Ward wants to keep working, both for the challenge of tackling new problems and to continue earning money. "It doesn't matter if I make money but that I have meaningful work as I define it," he said.

Combining work and mission

Lisa Sabourin describes herself as "a typical worker of my generation." She joined Investors Diversified Services out of college and rose into management roles over two-plus decades within what eventually became Ameriprise before finding herself on the wrong side of a divestiture in 2007. Seeking a change, she earned a mini-MBA in nonprofit management and applied, without success, for several jobs in that sector before heading back into the corporate world. Laid off again in early 2012, she took a different tack, throwing herself into volunteering for several nonprofits.

Sabourin figured she would "get to know people and get them to know me" with the goal of combining her business background with her desire to work in a mission-driven organization. That approach led to a temporary paid position at Catholic Charities that gave her the résumé she needed to land her current role as a project coordinator at the Emergency Foodshelf Network.

While she doesn't earn the income she did in her corporate roles, Sabourin finds a different measure of success. She gets paid to work at an organization where everyone shares a sense of mission.

"I have no plans to retire if my work is meaningful work," Sabourin said. "Finally I am where I wanted to be."

For more information on Shift programs, go to www.shiftonline.org.