Ah, the question everyone loves to debate. It's true that Social Security will soon start paying out more benefits than it receives in contributions, as the bulk of the baby-boom generation phases into retirement.
The government's official position is that there is enough money saved to pay benefits at the currently scheduled amounts until 2035. The Social Security Administration admits on its Web site that benefits will likely be reduced after that, barring changes that improve the financial strength of the system.
Social Security’s cash flow has been negative since 2010, meaning that the program has paid out more than it takes in via taxes. Right now it is covering that shortfall with interest on its Treasuries, but that can’t continue indefinitely. While it’s unlikely Congress will do away with Social Security, to close the gap it’s going to have to scale back benefits for future recipients, increase taxes, or both.