Retirement is a milestone that millions of workers look forward to. Some seniors, however, don't wind up as enamored with it as expected. An estimated 39% of Americans age 65 and older who are currently employed were actually previously retired, according to a 2017 Rand Corp study, and the reason doesn't just boil down to money.

Sure there are plenty of seniors who end up going back to work after attempting to retire due to financial concerns or constraints. But for many, it's more a matter of missing their jobs.

In fact, when asked what they miss the most about pre-retirement life, the most popular answer among retirees is work -- specifically, working with their former colleagues. And it makes sense. For many, work serves as a community of sorts and an opportunity to interact with different people, challenge oneself, and celebrate accomplishments. Retirement, by contrast, doesn't always serve as the same social outlet and often doesn't provide the fulfillment that comes with a job well done.

Older man sitting at a laptop, smiling

IMAGE SOURCE: GETTY IMAGES.

If you're aiming to retire in the near future but happen to enjoy your job, you may want to think twice before bringing a thriving career to a close. Here are just a few of the benefits you might enjoy as a result of working longer.

1. A larger nest egg

It stands to reason that the more savings you retire with, the more comfortable a lifestyle you'll enjoy. Working longer can help boost your nest egg in a number of ways. For each additional year you work, you'll get an opportunity to keep contributing to a retirement plan or another savings plan, but just as importantly, you'll hold off on tapping your nest egg while still collecting a paycheck. And that will make whatever savings you've amassed last longer.

Even if your savings are pretty robust to date, remember that once you retire, you're going to have a lot of free time on your hands -- and that time will cost money to occupy. Having a more substantial nest egg might buy you the flexibility to travel and enjoy your newfound free time to the fullest, and that's something that might soften the blow of eventually leaving a job you love.

2. Increased Social Security benefits

Another perk of working longer is the potential to boost your Social Security benefits. For each year you hold off on taking benefits past your full retirement age up until age 70, you'll increase them automatically by 8%. This means that if you're looking at a monthly benefit of $1,600 at a full retirement age of 67, waiting until 70 to file will give you $1,984 per month instead -- for life. And if you're still collecting your regular paycheck, it's safe to assume that you won't necessarily be in a rush to get your hands on that Social Security income right away.

3. Better health

One final reason it pays to work longer is that doing so has been linked to better health and a longer life. And clearly, that's a benefit unto itself. From a financial perspective, however, keeping yourself in good shape can lower your healthcare costs, thus saving you money on medical bills.

Remember, for some people, work serves as a form of physical exercise (whether it's the job itself or the commute). For others, it's a means of keeping the mind engaged. Either way, there's a lot to be gained healthwise by working longer.

The perfect compromise

If your main hesitation about retirement stems from having to leave your job but you're reaching the point where you're struggling to keep at it, a partial retirement may be the right choice for you. If you're a long-term employee in good standing, you never know what arrangement your company might be willing to agree to. If you can no longer manage the 40-hour-a-week grind, working 20 hours a week could be the perfect compromise. This way, you can take a load off while also enjoying the benefits of having a job to report to.

Similarly, if you're already retired but are missing your colleagues and office life, there's no reason not to approach your old boss and see if a part-time arrangement might work. It's a far better bet than walking around unhappy in retirement because you have too much downtime and too little to do.

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