Retiring cold turkey can be a shock to your finances — not to mention to your emotions and sense of purpose. If you are approaching retirement age and the prospect of such a sudden change worries you, consider drawing up a plan to work part-time so you can ease your way out of the working world at a pace that suits you.

Even if retirement is decades away, mapping out your path can prove to be a valuable exercise, because it will force you to think hard about what's important to you as you prepare for retirement. What, exactly, do you want to do with the next few decades? Do you want to keep working because you love your job, even if you really want to cut your hours to make time for travel? Would you rather move to the Colorado mountains or the Florida beaches, but continue using your work skills? Have you always dreamed of a second career, in a field you love but considered a hobby while you were toiling away in your first career?

If you answered yes to any of those questions, or simply want to slow down but haven't quite built a sufficient nest egg, phasing in your retirement by moving from full-time to part-time work could be the way to go.

One option is pitching the idea to your company, Paul Rupert, president of Rupert & Company and director of workplace flexibility consultancy Respectful Exits, tells Forbes. Start with a written proposal that positions your idea "as an investment opportunity for the company, not just as a personal request," Rupert says.

This might be a long shot — phased retirement is only a formal option at 5 percent of firms, according to a 2015 Society of Human Resources Managers report — but if it's what you want, it's worth a shot. And if the odds look tough, try getting like-minded colleagues to join you in a group pitch for a pilot phased retirement program at your company, Rupert suggests to Forbes. "It really can work out in ways you can't imagine," Rupert says, "and it can help make your last few years of work, the best years."

Another possibility, says Kerry Hannon at AARP.org, is to start laying the groundwork early while you're still working full-time so you can transition into a part-time job, maybe in a new line of work you've always wanted to try. Have you always dreamed of transforming your love of cooking, or baking, into a second career? Try catering or baking on weekends, slowly building your clientele while you're still working full-time, then opening a small business when you're ready to start your second act.

"For those who want to step away from a current career and work part time at something different, the possibilities are endless," Hannon says. "In fact, making a decision about what to do next can be daunting." AARP keeps a library of information to help people research opportunities that might be right for them.

The idea of easing into retirement this way is getting increasingly popular. Nearly 20 percent of Americans 65 and older were working last year, the most since Medicare started in the 1960s. That's nearly twice the proportion in 1985, when 10.8 percent of those 65 and older were still in the labor force, according to USA Today, citing the Labor Department and AARP. The figure could continue to rise, as about a third of 45- to 65-year-olds in a recent IPSOS/USA Today survey said they planned to work part-time in retirement, with 4 percent hoping to continue working full-time.

People who go this route, Hannon says, can "keep doing something they enjoy, continue earning, save more money, and gain the advantage of more time off."