Running out of money in retirement is a major worry for Americans of all ages, but particularly those who are older with less time to build savings. And given that the average U.S. household aged 56 to 61 has just over $163,000 in retirement savings, according to the Economic Policy Institute, it's an extremely valid concern.

However, it's not just folks with limited savings who fear they'll prematurely deplete their nest eggs. In a new Allianz study, 66% of Americans aged 45 to 65 with over $400,000 in retirement savings on average feel they're at risk of running out of money during their golden years. And 61% think they'll need to keep working later in life rather than retire to mitigate that risk.

Older man writes in a notebook while woman looks on

Image source: Getty Images.

Of course, this begs the question: If older Americans with decent savings feel they're likely to fall short, what will the future have in store for those who are glaringly behind?

Making up for lost time

It's one thing to have a paltry nest egg in your 20s and 30s, when retirement is still several decades away. But there comes a point in your career when you can no longer afford to put off saving money -- and many adults have already let too much time go by without setting aside funds for the future. An estimated 33% of Americans 55 and over have less than $10,000 in retirement savings, according to GOBankingRates. That's downright disturbing, especially when we consider that Social Security isn't enough to sustain seniors by itself.

So what should you do if you haven't saved enough for retirement and are already pretty far along career-wise? A few things. First, aim to take advantage of catch-up contributions in your 401(k) or IRA. If you're 50 or over, you can contribute up to $24,500 a year to the former and $6,500 a year to the latter.

Where will that money come from? It might stem from your efforts to cut major corners in your budget. While cutting back on store-bought coffee or lowering your cable plan probably won't have a huge impact, downsizing your living space or getting rid of a second household vehicle will, so aim to reduce at least one significant expense you're currently paying for.

Another option? Take on a second job to drum up extra cash. Since that money won't already be earmarked for another purpose, you should, in theory, have no problem sticking it directly into your nest egg. In fact, 14% of Americans who have a side hustle do that additional work for the express purpose of building retirement savings.

While you're making changes at present, make plans to work longer than you initially expected to. Imagine that instead of leaving your career behind at age 67, you keep plugging away until 70. If, during that time, you manage to max out a 401(k), and your investments deliver a decent (though not too aggressive) 6% return, you'll pad your nest egg by $78,000. At the same time, you'll hold off on taking withdrawals from your existing savings, thus allowing them to last longer.

Working longer can also help boost your Social Security income. For each year you hold off on filing for benefits past full retirement age (FRA), your payments will increase by 8%. This means that if you're looking at a monthly benefit of $1,500 at an FRA of 67, waiting until 70 to file will leave you with $1,860 a month instead -- for life.

No matter how much money you've saved for retirement, the reality is that you can really never have too much. So if you're worried you'll run out in the future, take steps to pad your nest egg, even if it means making some sacrifices along the way.