The scary thing about retirement is having to move over to a fixed income while your expenses have the potential to rise. It's for this reason that we all need a healthy level of retirement income -- enough to pay our bills and, ideally, have enough left over to enjoy post-work life. But a recent Transamerica survey indicates that many seniors are putting their retirement at risk for one big reason: They're relying too heavily on Social Security.

Specifically, 69% of retirees say that Social Security will be their primary income source throughout their golden years. But that's a mistake they might sorely regret.

The problem with banking on Social Security

Many seniors look to Social Security as a reliable income source. But those benefits may be reduced in the not-so-distant future.

Social Security card

Image source: Getty Images.

In the coming years, Social Security expects to have higher financial obligations than revenue as baby boomers leave the workforce and start collecting benefits. The program's primary revenue source is, in fact, payroll taxes, so a mass workforce exodus could result in a significant monetary shortfall. Social Security does have trust funds it can tap to keep up with its scheduled obligations, but once those funds run dry, benefit cuts will, unfortunately, be on the table.

Of course, the question of when the program's trust funds will run out is still up for debate. Earlier in the year, the Social Security Trustees projected that they'd be out of money by 2035, making that the first year for potential benefit cuts. But a lot has happened since that estimate was rendered -- namely, we've had a pandemic that's caused an unprecedented unemployment crisis.

Remember Social Security's primary revenue source -- payroll taxes? The program has been collecting a lot less of that since the COVID-19 outbreak began, and as such, there's a good chance its trust funds will be depleted much sooner than initially anticipated. And that means benefits may be cut even earlier, leaving seniors who rely on them primarily for income deep in the lurch.

Still, that's not the only reason to not bank so heavily on Social Security in retirement. The other reason is that Social Security will only replace about 40% of your previous income if you earned an average wage. Most seniors, however, need roughly twice that amount to keep up with their expenses. And let's also not forget that Social Security has historically done a poor job of keeping pace with inflation, so seniors who rely a lot on their benefits ultimately end up losing buying power from year to year.

A better solution for your retirement income

While there's nothing wrong with getting some of your income from Social Security, it really should not be your primary source during retirement. Rather, that role should fall on your savings. Or at the very least, your savings and Social Security should be equal partners in this regard.

Of course, if you're retired already, you can't go back in time and fund an IRA or 401(k) plan. But if you're not yet retired, you can take the opportunity to boost your savings so you're less reliant on Social Security once your time in the workforce comes to an end.

If you sock away $500 a month in an IRA or 401(k) over the next 20 years and your investments generate an average annual 7% return, which is a bit below the stock market's average, you'll wind up with a $246,000 nest egg. And that assumes you only have a 20-year savings window ahead of you. Save $500 a month for 30 years and you'll have $567,000, assuming that same 7% return.

Many seniors right now may be in for a financial shock if Social Security benefits are cut. But if you save aggressively between now and retirement, you'll end up in a very different and far more favorable boat.