AbstractDeposit insurance involves catastrophe risk because bank failures spike during a banking crisis. Although mutual insurance is ill‐suited for catastrophe risk, the US government structures deposit insurance like a mutual company owned by policyholders. Furthermore, an intertemporal mispricing resulting from a dividend‐surcharge arrangement produces several problems. Most importantly, it worsens moral hazard. Through dividends and surcharges, deposit insurance transfers the premium burden from high‐risk banks to low‐risk banks and in effect erodes the charter value of low‐risk banks. In addition, high‐risk banks taking catastrophe risk can outperform low‐risk banks for many years in a row, putting pressures on managers of low‐risk banks. Owing to these factors, an underpricing of catastrophe risk before its realization can ratchet up risk‐taking by banks. Other problems with the intertemporal mispricing include making the banking business more procyclical, distorting the prices of banking products, and exposing taxpayers to asymmetric downside risk. To ensure fair competition and improve economic efficiency, the government should set the insurance premium based not on the realized loss but on the expected loss.