Because Social Security won't be enough to sustain the average American in retirement, it's critical to save independently for the future. But unfortunately, a large number of near-retirees are glaringly behind in this regard.

According to the Economic Policy Institute (EPI), the average household aged 56-61 has $163,577 available for retirement. And while that might seem like a decent chunk of cash, it actually only translates into $6,543 a year over a 25-year period. Furthermore, while the average savings balance for baby boomers is $163,577, the median balance for that age group is a mere $17,000, which means that many older workers have much less than the average. Worse yet, the EPI also reports that more than 40% of baby boomers have no retirement savings at all.

Senior couple looking at a tablet outdoors

Image source: Getty Images.

If you're behind on retirement savings and are nearing the tail end of your career, now's the time to play catch-up before it's too late. Here's how.

1. Start maxing out your retirement plan contributions

The good thing about being an older worker is getting an opportunity to contribute more to a retirement account than your younger counterparts. Once you reach age 50, you're allowed to put up to $24,000 per year into a 401(k) and $6,500 per year into an IRA. Max out the former option for seven years, and even if you stick to safe investments with minimal growth, you'll have at least $168,000 to your name, which is just above what the average boomer has today.

If you can't max out your retirement plan contributions, aim to at least increase your savings rate. If you're currently contributing $400 a month to a 401(k), cut back on some living expenses and bank an extra $200 a month. Over seven years, you'll pad your nest egg by $16,800 -- and possibly more when you factor in investment growth.

2. Work a few extra years

It's hard to catch up on retirement savings when you only have a few more years on the job to work with. So if you want to avoid a cash-strapped retirement, it pays to think about extending your career for a number of years and setting aside as much cash as possible during that time.

Imagine that instead of calling it quits at age 67, you push back your retirement date until age 69, during which time you're able to max out your 401(k). Not only will you have an extra $48,000 to work with in retirement, but just as importantly, you'll avoid dipping into your existing savings during those 24 months, thus stretching them further.

3. Get a side job

If you're behind on savings but don't want to delay your retirement, you might consider finding a side gig in addition to your day job. According to a just-released Bankrate study, 44 million working Americans currently have some sort of side hustle that helps them bring home extra cash. In fact, of those who work a second gig, more than one-third manage to earn an additional $500 a month.

If your regular salary doesn't allow for much in the way of savings, but you work a side job for three years and take in $500 more a month during that time, you'll have a chance to amass an additional $18,000, which can work wonders for your nest egg. Furthermore, if your side hustle proves lucrative, and it's something you enjoy doing, you can plan to maintain that gig during retirement and generate extra income that way.

4. Unload an expensive home

Housing is the typical working American's single largest monthly cost. If you're spending a huge chunk of your income on a hefty mortgage payment and high property taxes, moving to a less expensive home could potentially free up thousands of dollars per year to set aside for retirement. Chances are, if you're nearing retirement, your children have already moved out and you don't need the same amount of space or amenities you once did, so if you're willing to relocate, you might salvage your retirement after all.

5. Adopt a smart investment strategy

Many near-retirees stay away from stocks because they're afraid of taking the risk when they're older. But while it's a good idea to shift some of your investments out of stocks as retirement gets closer, as long as you have a good seven years (or more) to go in the workforce, you should feel reasonably comfortable keeping a chunk of your portfolio in the stock market.

Keep in mind that you don't need to hold individual stocks to get a piece of the action. A less risky approach involves investing in index funds, which offer built-in diversification by simply tracking existing market indexes and aiming to match their performance.

Just how much of a difference might that make for your nest egg? It obviously depends on how the market performs, but say you have $100,000 to work with in your portfolio, and you decide to put that entire sum into bonds. If your investments produce an average annual 4% return over a seven-year period, you'll grow that balance to $131,000. Go with stocks, however, and you might score an average yearly 8% return, which, in turn, will leave you with $171,000.

Just because you're behind on savings doesn't mean your retirement is doomed. If you take steps to make up for lost time, you can establish a sizable nest egg and enjoy the comfortable retirement you've always dreamed of.