The Federal Deposit Insurance Corporation (FDIC) is a United States government corporation supplying deposit insurance to depositors in American commercial banks and savings banks. The FDIC was created by the Banking Act of 1933, enacted during the Great Depression to restore trust in the American banking system. More than one-third of banks failed in the years before the FDIC's creation, and bank runs were common. The insurance limit was initially US$2,500 per ownership category, and this has been increased several times over the years. Since the enactment of the Dodd–Frank Wall Street Reform and Consumer Protection Act in 2010, the FDIC insures deposits in member banks up to $250,000 per ownership category. FDIC insurance is backed by the full faith and credit of the government of the United States, and according to the FDIC, "since its start in 1933 no depositor has ever lost a penny of FDIC-insured funds".

A bank run or run on the bank occurs when many clients withdraw their money from a bank, because they believe the bank may fail in the near future. In other words, it is when, in a fractional-reserve banking system, numerous customers withdraw cash from deposit accounts with a financial institution at the same time because they believe that the financial institution is, or might become, insolvent. When they transfer funds to another institution, it may be characterized as a capital flight. As a bank run progresses, it may become a self-fulfilling prophecy: as more people withdraw cash, the likelihood of default increases, triggering further withdrawals. This can destabilize the bank to the point where it runs out of cash and thus faces sudden bankruptcy. To combat a bank run, a bank may acquire more cash from other banks or from the central bank, or limit the amount of cash customers may withdraw, either by imposing a hard limit or by scheduling quick deliveries of cash, encouraging high-return term deposits to reduce on-demand withdrawals or suspending withdrawals altogether.