Nearly a third of preretirees will change careers by 2019, many looking for less stress and a better work-life balance, according to a USA TODAY survey. Multiple career changes are increasingly commonplace, and those over 50 have plenty of opportunities ahead of them. As entrepreneurial fever continues to grow, young startup entrepreneurs are looking toward more seasoned workers and partners to add a little gray hair to the hipster set to achieve just the right balance.

Giving Back to the World

A second career isn't always about the money, and 33 percent of retirees chose second careers to "give back" to their communities. You may also wish to transition into work in the nonprofit sector. A common theme among all job counselors working with 50-plus clients is that they want to do something meaningful, keep mentally engaged and leave a legacy while making a difference.

Subtle Switch or Extreme?

Second or third career moves aren't always dramatic. Although anecdotal stories of people leaving a career in finance to join a dance troupe do exist, a more subtle switch is far more common. An accountant for a Fortune 500 corporation may find a higher calling doing the books for a neighborhood nonprofit, for example. Naturally, the money is likely to be less in the nonprofit world, and this sort of second career move may require rethinking one's personal budget and downsizing.

Tech and Dot-coms

There may be a perception that the tech industry is dominated by 30-year-olds who wear hoodies and ride skateboards to work, but especially as the baby-boomer population continues to age, the tech industry is getting older. You may have earned a degree a few decades ago, but that doesn't matter much any more, as recertification no longer requires years of study — and the younger people running the show at big tech firms are beginning to acknowledge the wealth of experience that older workers bring to the table.

In fact, the boomer generation has done better than other age groups in terms of education, with 25 to 30 percent of the demographic having college degrees. Going forward, the tech industry will be increasingly turning to older workers to do everything from working in the call center to programming and coding and lending their expertise to running the show in terms of marketing, logistics and management.

Encore careers in the tech field are abundant, with several tech careers growing rapidly. The U.S. Bureau of Labor Statistics projects 186,600 new jobs for computer software developers by 2024, and 118,600 jobs for computer systems analysts.

Call Centers

Call center agents are always in high demand, and are well suited to the over-50 crowd looking for a second career. The role can be something as simple as direct sales, providing customer service or dealing with general inquiries. While some of these jobs may call for sales experience, others are more straightforward. A big benefit of a larger call center is that it offers opportunity for advancement to positions as team leader or call center manager, and the your experience will be very much in demand.

The Entrepreneurial Path

Although some successful tech startups began in college dorm rooms with people not yet old enough to drink, those high-profile stories are outliers. The reality is different. High-growth startups are twice as likely to be launched by people over 55 as by people between 20 and 34. A Kauffman Foundation study showed that Americans between 55 and 64 start new businesses at a higher rate every year than those in their 20s and 30s, and the trend is growing. The new generation of startup companies requires the deep experience and cross-disciplinary skills of the older and more experienced entrepreneur, and new business startups will present a greater opportunity for you to start a new career after 50.

Careers in Health Care

According to AARP, some of the fastest-growing jobs for people over 50 are in the health-care field, with 348,400 new home health aide jobs projected by 2024 and median wages of $22,600. Other similar health-care jobs that require only short-term, on-the-job training include personal and home care aide. Only moderate on-the-job training is necessary for the 138,900 new jobs as medical assistant projected by 2024.