Half of retirees say they retired earlier than they had planned. You should be ready. (Jakub Jirsak)

A third of Americans expect to work at least until age 65. Another 10 percent don’t plan to retire at all.

Many don’t think they’ve saved enough money. And baby boomers are redefining retirement and must keep busy to stay happy — especially if many expect to live into their 80s and 90s.

But they are in for a shock. A 2015 Employee Benefit Research Institute survey found that 50 percent of retirees left their jobs sooner than planned. Why?

Half had to leave because of disability, a health issue or to care for someone close to them. Another 18 percent left because of layoffs or downsizing.

“We always try to tell people you should be prepared for that every day,” says Nancy Coutu, co-founder of Money Managers Financial Group in Oak Brook, Ill. “Even if the plan is to work forever, Mother Nature often does things out of control, and you are forced into retirement.

“Bad things happen to good people,” she says. “You could be best worker on the planet, but no one in indispensable.”

What can you do to prepare? Financial advisers and retirement experts offer some tips. Just in case.

Do a budget. “If you have time to plan, the most important thing is to have detailed budget of cash inflows and outflows,” says Michael Dalton, author or co-author of more than 100 books on financial planning. “That’s the only way you know where money is coming from and where it’s going.”

Coutu agrees that this step is critical. “First they run numbers to see if there is a deficit,” she says. “Then we figure out how much they have to make. A lot will go back to work making less. Or they may have to get a part-time job. If they want to maintain current lifestyle and can’t find a full-time job, we look at real estate. We look at downsizing and if they have to do a reverse mortgage. “

Make extra payments on your mortgage and car. “Management of housing expenses is a critical item, because it’s the biggest,” Dalton says — about 40 percent on income.

The strategy here is simple. If you are 55 and worried about losing your job at 60, make additional mortgage payments. So, if you have a 30-year-mortgage with 23 years left, try to pay it off in seven. Similarly, look at automobile payments, he says. “I need to get the car paid off around the time I am at the highest risk of being terminated,” Dalton says.

“Pay down debt,” says Greg Hammer, president of Hammer Financial Group. “If you are married, ask yourself, ‘Where would we be if we only had one income?’ If you have an unexpected retirement, most will not be prepared.”

Boost your emergency savings. “We tell people to pay yourself first,” Hammer says. “You should have six months of cash reserves. And if you are eligible, you should be contributing to a Roth IRA. Principal dollars can be pulled out at any time after you reach 59. You can stretch those dollars.”

Paul Bennett, managing director of United Capital Financial Advisers in Great Falls, says six months of savings is not always possible, so there are alternatives. “Sometimes they will rely on untapped home equity to act as bridge,” he says.

Have a plan. Coutu had clients who had a long-term plan: Upon retirement, they would sell their home and move to Arizona. “Out of nowhere the husband lost his job,” she said. “We went back to drawing board. I asked the wife, ‘If he can’t find a job, what do you want to do?’ She said if he’s not working, she’s not working.

“We accelerated their plan,” she said. “I said, ‘Let’s work it out on paper.’ We looked at what Social Security would be, what the pension would be, what we would get for the house, what it would cost for the dream house in Arizona. It turned out they could go right now. They sold their house and are living in Arizona. Because they had been planning for years, it was a wonderful success story.”

Consider disability insurance. “Personally, if someone is disabled, it is critical that they have a disability policy to protect their biggest asset — ability to earn a living,” Bennett says.

Similarly, he says, some people leave jobs because their parents are facing long-term health issues. “That can create a real problem. One way to cover that is to consider purchasing long-term care insurance for your parents if they can’t afford it. The costs on average in this area are over $10,000 a month for nursing-home care.”

Keep your skills current and your résumé up to date. “Keeping your skills sharp, keeping your résumé updated, staying active on professional networks is imperative,” Bennett says.

But lower your expectations for salary and benefits if you do land another job. People over 50 separated from their jobs often find it nearly impossible to find similar jobs and salaries.

If the layoff happens, negotiate your severance, especially health insurance. Dalton said that when he was bought out by a university, he secured group health insurance, even though he pays the premiums. His goal was to keep it going until he qualified for Medicare. “What you do about health care is critical,” he says. “Fortunately, under Obamacare, you don’t have to worry about preexisting conditions. “

“Plan for the future like I may not have a job tomorrow,” Coutu says. “People need to make sure they don’t outlive their money.”

Delayed retirement

In the past year, 13 percent of workers report increasing the age they expect to retire, compared with 22 percent in the 2013.

2008-2015 Retirement Confidence Surveys