Waiting till 70 is often advised due to longer life spans, but sometimes starting sooner makes most sense. (iStock/iStock)

If there is one piece of advice that financial advisers seem nearly unanimous on, it’s Social Security and when you should take it. If you can, wait till you’re 70. You could double your monthly check.

Granted, it may be good advice, but few people take it. It makes you wonder: Is there a disconnect between financial planners and “real people”?

In fact, most Americans don’t wait that long. According to the Social Security Administration, 37 percent of people take benefits at 62, as soon as they are eligible. Another 18 percent take benefits at full retirement age (66 for most baby boomers), and only 3 percent waited until 70.

But the problem is that life expectancies are ever increasing — to nearly 80, according to the last report from the Centers for Disease Control and Prevention. If you live till 65, you are likely to live another 18 to 20 years, depending on your sex.

If you take Social Security before full retirement age, you lock in a 25 percent reduction for the rest of your life. If you wait till you are 70, you can get an additional 32 percent boost in monthly benefits (or roughly 8 percent for each year you wait).

So should you take it at 62, 66 or 67? Or wait till 70? Truth is, it depends.

“Generally speaking, if it’s at all possible, it’s best to delay taking Social Security at least until you reach full retirement age,” says author Lynnette Khalfani-Cox, chief executive of TheMoneyCoach.net. “Of course, that’s easier said than done because most Americans who haven’t saved enough for retirement probably feel like they don’t have any other good option.”

“Social Security is not always a black-and-white answer,” says Jennifer Landon, founder and president of Journey Financial Services in Idaho Falls, Idaho. “We have software that helps us compare different strategies.”

Often, based on life expectancy, the software says wait till 70, she says.

“I always say it depends on circumstances,” Landon says. “It depends on how much they have saved up.” For instance, if it looks like the client will be forced to withdraw too much from their savings early in retirement, she will recommend that they take Social Security early.

Mary Beth Franklin, a contributing editor at InvestmentNews, says the key is to make an educated decision. She recommends people wait until 70 if they are healthy, have other income or assets they can tap, or can keep working.

“If you have two working spouses, if at least one of them can wait it is a great way to hedge your bets,” she says. “You are assured that one spouse will get a bigger benefit and lock in a bigger survivor benefit.”

The details of Social Security planning can be daunting, says Ron Grensteiner, president of American Equity in Des Moines. “That would lend itself to someone making the easiest decision . . . get it when you can . . . at age 62.”

“Very few people are waiting until age 70 to claim,” he says. “And really, there isn’t an optimal guideline for when to claim. It depends on each person’s situation regarding health, finances, family situation, job status, etc.”

Maya Rockymoore, chief executive of Global Policy Solutions, a social change strategy firm, says taking Social Security early for some is a “rational” decision.

“People retire for different kinds of reasons,” Rockymoore says. “When people say wait for normal retirement age or 70 so you can get most out of it, they mean maximizing the financial benefit. African Americans take early retirement disproportionately, and many times it’s because of health. African American men are hedging their bets. They paid in for all their lives — they know fathers and brothers had short lives — and they are looking to get something out. It is a logical and rational decision.”

Khalfani-Cox says the challenge for African Americans of when to take Social Security is tricky, since life expectancy is shorter for blacks, particularly black men, and wages for African Americans tend to be lower than their white counterparts. “Additionally, blacks more heavily rely on Social Security, with about one-third of African American couples and more than half of older, unmarried blacks counting on Social Security for nearly all of their retirement income.

“Despite these realities, most folks — including many African Americans — take Social Security as soon as they can, at age 62,” she says. “That’s a mistake since you could wind up living for two or three decades more and, if so, you want your Social Security benefits to be as large as possible.”

Khalfani-Cox cites some alternatives to help people hold off taking early Social Security benefits: Save more during working years, stay in their jobs longer, or work part-time in retirement.

Willie Schuette, a financial planner for the JL Smith Group in Cleveland, says the primary reason people take benefits early is because they need the money. “People need that income the day they retire from their current job,” he says.

Schuette says he sometimes recommends that his “middle-class millionaire” clients take it early even if they can afford to wait.

“They are in the best shape of their lives,” he says. “There are so many things they can do in their 60s and enjoy that money. The might upgrade a trip, might go first class. They might go to Europe. Whatever lifestyle goals may be. It could be a recreation vehicle.” Some clients just give the money to their grandchildren, he says.

Most times, the recommendation to wait till 70 is made because the financial planner industry is trying to maximize client dollars in retirement, he says, but that may not necessarily be the client’s goal.

Franklin says she has a family member who works in a nursing home who believes people would be amazed at the residents there who are 90 and older.

“People always underestimate how long they will live,” she says. “How long did my parents live? That’s history,” she says. “When we look at longevity of course, we just have no idea. Kids today may live to 110 or 120. We’re not sure. Longevity is a real issue in retirement planning, and problem is nobody knows the right answer until you’re dead.”