Heading toward retirement, but you want to keep working? The best move is to find another job in your field, perhaps part-time or or as a consultant—right? Maybe not. Sure, you’ve amassed tons of expertise in your industry after working in it for the past decade or two. But there’s a wider world out there. Many older Americans are opting for a completely different career after they leave their former jobs, according to a new Merrill Lynch survey on work and retirement. Nearly 50% of retirees say they either have, or intend to, stay employed during their retirement, according to the survey. Not a surprise, given today’s meager 401(k) balances. But what’s striking is how many people ended up with brand new careers.Nearly 60% of working retirees are in jobs that are completely different from their pre-retirement work, with many in education and white-collar jobs, according to demographers Age Wave, who contributed to the study. Working retirees also tend to be entrepreneurs. They are three times more likely than other workers age 50 and older to own their own business or be self-employed, according to the study, which gathered data on nearly 7,000 pre-retirees and retirees, both working and non-working. “Retirees often make for the best entrepreneurs. Many have decades of experience, business contacts and the financial means to start a successful business,” says Bill Hunter, director of personal retirement strategy at Bank of America Merrill Lynch. While some retirees are working primarily for the income, more report doing it to stay busy and involved: 62% of working retirees say they work to stay mentally active, compared with 31% who say money is the top reason. Busting another myth, most older entrepreneurs say age discrimination didn’t drive them to work for themselves: 82% of these “retire-preneurs” as Merrill Lynch is branding them, say they started their own business because they wanted to work on their own terms. Only 14% reported that they had to start their own company because they otherwise couldn’t find work. “Working in retirement is often a chance to try something new or pursue a dream,” says Mary Beth Izard, a start-up consultant and author of BoomerPreneurs. If a brand-new second act appeals to you, start developing your plans now. Taking on a new career challenge in your retirement years isn’t easy, and a start-up venture can drain your nest egg fast. Lay the groundwork in the five years before you plan to retire, says Izard. If you want to go into a new career, begin by taking classes, as well as working part-time or or as a volunteer for an organization involved in the field you are interested in. And if you go the entrepreneur route, starting researching the costs and income potential of that new business well before you start sinking money into it. For more tips on embarking on an entreprenurial second act, click here.