A systemically important financial institution (SIFI) is any firm whose failure could pose a threat to the financial stability of the United States because of its size, its complexity, or its potential riskiness because it isn’t sufficiently regulated by the government. A firm designated as a SIFI is subject to enhanced rules of financial oversight from the Federal Reserve System. The stricter oversight includes increased costs for the SIFI in the forms of (a) higher Tier 1 capital requirements, (b) annual stress tests, and (c) detailed “living wills” in the event the firm should fail.