Max Richtman is president and CEO of the nonprofit National Committee to Preserve Social Security and Medicare. He is former staff director of the Senate Special Committee on Aging. The opinions expressed in this commentary are his.

(CNN) There are many myths about Social Security: It's going bankrupt. It's a Ponzi scheme. It won't be there for today's young people when they retire.

There's no truth in any of them.

But one of the most prevalent myths these days is that the federal government is stealing from Social Security. It goes something like this: The President and/or Congress have been raiding the Social Security Old Age and Survivor's trust fund (also known as the retirement trust fund) to pay for other federal expenses (tanks, roads, bridges, food stamps, etc.) and have never paid it back. The myth, which persists today, goes back at least 50 years and is based on a fundamental misunderstanding of Social Security's finances

Contemporary politicians have helped perpetuate the "stealing from Social Security" falsehood. During the first GOP debate of the 2016 election cycle, then-New Jersey Gov. Chris Christie claimed , "The lying and stealing has already occurred. The Trust Fund is filled with IOUs." Others -- from Rand Paul to Mitt Romney -- have insisted that the government pilfers Social Security funds for unrelated purposes.

But conservatives aren't the only ones to blame for perpetuating this myth. "Next time a Republican tells you that 'Social Security is broke,' remind them that Pres. Bush 'borrowed' $1.37 trillion of Social Security surplus revenue to pay for... his war in Iraq and never paid it back," claimed Occupy Democrats' Facebook page

Some members of the public have also bought into the "stealing" myth. Every week, I see comments on social media that bear this out. Here is just a small sample:

"Can we get the government to pay back what they stole from social security? Take it out of the military budget because I'm sure that's were it went." Or, "The Government has been stealing & borrowing from the fund & never paying it back for years. When they run short they come up with a lie to make cuts & take more."

These commenters are no doubt well-intentioned, but they are woefully misinformed on this issue. Here is the truth: Every year since 1984, the Social Security system has had more income than it needs to pay current benefits and administrative costs, so it invests the surplus in interest-bearing government bonds , backed by the full faith and credit of the US Treasury.

Why put the surplus payroll funds in Treasury notes? If you had $2.8 trillion in extra cash , wouldn't you want the money to earn interest instead of stuffing it under your mattress?

The same goes for the Social Security system. As the Social Security Administration explains : "The Social Security trust [fund] holds money not needed in the current year to pay benefits and administrative costs and, by law, invest[s] it in special Treasury bonds that are guaranteed by the U.S. Government."

In fact, you can check the status of these bonds at any given time on the Social Security Administration website

Clearly, there is no stealing going on here -- just investing and earning interest. So, why the myth? As author Kurt Andersen pointed out in his recent book, How America Went Haywire , Americans love conspiracy theories, which the 'stealing' claim surely is. It also helps stoke populism on the left and right -- and the mistrust of government that has been fermenting since the 1960s.

Much as we might like to dismiss the 'stealing' narrative as harmless, it actually does undermine the Social Security program in its own way. Claiming that workers' hard-earned payroll contributions are being 'stolen' undermines public confidence in Social Security itself, which has been under attack from fiscal conservatives for decades now. The myth helps feed the right-wing narrative that the program is ' going bankrupt ' and must be ' reformed ' (a code word for cutting benefits and raising the retirement age).

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While it's true that if Congress takes no action whatsoever, Social Security will only be able to pay 77% of benefits beginning in 2034, the program is hardly going bankrupt. Our organization supports modest and manageable measures to fortify the system's finances and expand benefits, including legislative proposals from Sen. Bernie Sanders (I-VT) and Rep. John Larson (D-CT), among others, that would keep Social Security solvent for decades. These measures boost revenue by increasing the amount wealthier Americans contribute in Social Security payroll taxes (currently capped at $128,700 in annual income), while modestly boosting benefits and adjusting the formula for cost-of-living adjustments to more accurately reflect retirees' true expenses.