NEW YORK (Reuters) - When you envision retirement with a partner, what does it look like?

Probably retiring at the same time, as you both wave goodbye to the workforce and look forward to new adventures.

The reality is that only 11% of American couples actually retire at the same time, according to a survey by financial services firm Ameriprise.

In fact, 62% of couples end up retiring more than a year apart, the firm's Couples, Money & Retirement research found.

This disconnect requires us to rework almost all of our retirement assumptions, which include: the money coming in; the money going out; the healthcare coverage needed, and the Social Security decisions.

All of these assumptions are deeply affected by so-called staggered retirement dates.

"Couples stagger their retirements for different reasons," said Nayan Ranchhod, a private wealth adviser for Ameriprise who analyzed the data.

And it is not usually about the money - "although that definitely does help," Ranchhod added.

After all, in addition to the financial ramifications of staggered retirement, there are the emotional ones as well, including how couples feel about one partner still working and the other tapping on their shoulder wanting to take a trip somewhere.

The key here is to acknowledge this retirement reality, plan for it and make it work for you instead of getting taken by surprise.

Here are a four reasons why staggered retirements can make sense.

ADDITIONAL INCOME

Financially speaking, there are multiple reasons for one spouse to keep working for a few years, rather than the couple shutting off both income spigots all at once.

No. 1, you will keep salary coming in - which means you could continue to build up retirement savings, or at least not draw them down too hastily. In terms of the retirement math, the value proposition of a couple more years at the office is massive.

"Many couples stop making retirement plan contributions and budget based on the working spouse's take-home pay, which is now larger since they aren't putting money in the 401(k)," said Dana Anspach, a financial planner in Scottsdale, Arizona. "This allows them to put off account withdrawals as long as possible."

HEALTHCARE COVERAGE

Let's say you have a terrific healthcare plan through your workplace - a plan that covers your partner, as well. After 65 you qualify for Medicare, of course. But do you really want to give up a gold-plated plan early, if you do not have to?

"One of the most impactful reasons for one half of a couple retiring before the other is if one of them isn't 65 yet, and they can still get health insurance through the spouse's employer," said Tricia Rosen, a financial planner in Newburyport, Massachusetts. "That is a significant cost savings."

For whatever big procedures you may have been putting off - a knee or hip replacement, for example - it might be wise to have them done while you still have private coverage and head into retirement years with some major health concerns out of the way.

SOCIAL SECURITY BOOST

The long-term implications of delaying your Social Security checks are huge. With one partner working a couple more years, and both of you living off of current income, you can guarantee bigger monthly sums for the rest of your lives.

For example, if you start taking Social Security at age 62, you will receive a reduced benefit from that point on. But by qualifying for "delayed retirement credits," you get the biggest monthly benefit by not taking Social Security until age 70.

DIFFERENT RETIREMENT READINESS

As close as you may be as a couple, the reality is that you are two individuals, with your own thoughts and feelings about retirement.

In other words, one person may be emotionally ready for that life shift, and the other may not be. Just make sure that radically different retirement schedules do not lead to other relationship issues, such as guilt or loneliness.

"I have seen nonretired spouses get resentful from 'Fear of Missing Out' related to the first spouse's retirement, or even critical about the way the retired spouse spends their time," said Edward Silversmith, a financial planner in Pittsford, New York. "I think it's important for both partners to be on the same page about what retirement for the first spouse will look like."

(Reporting by Chris Taylor in New York; Editing by Lauren Young and Matthew Lewis)

By Chris Taylor