The U.S. Social Security system paid out almost immediately the money it took in. Thus, it was not funded:

Question

Quizplus · Accepted Answer

The fact that the Social Security system paid out almost immediately the money it took in means that it was not funded like a bank or an investment company, which rely on accumulating savings over time to generate interest or returns. It was also not funded like a profit corporation, which aims to generate profits for its shareholders. Instead, the Social Security system operates like insurance, where current workers pay into the system to provide benefits for current retirees or other beneficiaries.

The US Social Security System Paid Out Almost Immediately the Money