Most of us are familiar with Social Security. It's a program we all pay into during our working years and collect from in retirement. Those benefits are often crucial in helping retirees stay afloat, especially those without a whole lot of savings. But Social Security is by no means designed to sustain seniors in the absence of outside income, and relying on those benefits too heavily could set you up for financial ruin during retirement.

Unfortunately, 35% of workers today risk doing just that. That's how many expect Social Security to serve as a major income source during retirement, according to a recent survey by the Employee Benefit Research Institute. But that's a mistake that could prove catastrophic down the line.

Four Social Security cards loosely stacked on top of each other

Image source: Getty Images.

What role should Social Security play in your retirement?

Social Security will likely replace about 40% of your pre-retirement wages if you're an average earner. Most seniors, however, need roughly twice that much to live comfortably. As such, if you're expecting Social Security to be a major income source and are neglecting your savings, you may be setting yourself up for financial disaster.

Furthermore, that 40% income-replacement target assumes that benefits aren't cut in the future. Right now, the Social Security Trustees predict that the program's trust funds will run out of money by 2035. Once that happens, recipients may be looking at upward of a 20% reduction in benefits across the board.

So relying heavily on Social Security to sustain you in retirement is a bad idea. Can you factor those benefits into your financial planning? Sure. But don't make them your primary income source when you're older, especially since we don't know if cuts will end up happening. Try to save now for your senior years by spending less than what you earn and socking the rest away in an IRA or 401(k) plan.

You may be thinking, "I can't afford to save for retirement, so Social Security will have to do."

But consider this: If you're 40 years away from retirement and you can set aside $200 a month over the next four decades, you'll wind up with about $479,000 if your invested savings deliver a 7% average annual return during that time, which is a few percentage points below the stock market's historic average. Make it $250 a month, and you'll be sitting on about $599,000.

Of course, saving for retirement can be challenging when you're not used to budgeting for it. But would you rather adjust your spending habits now to secure your future, or risk spending your senior years barely scraping by?

Though Social Security is not in danger of going away, it shouldn't serve as your primary means of retirement income. The sooner you realize that, the sooner you can take steps to avoid financial struggles at a time in your life when you really don't deserve them.