The electric power grid is one of the most complex engineered systems today. Managing thousands of transmission assets spanning many miles and interconnecting regions and countries together combined with optimizing many generators with complex operating requirements creates a very challenging scheduling problem. Such a challenging problem becomes even more complex with resource uncertainty and stringent reliability standards. In order to solve such complex optimization problems within reasonable timeframes, approximations are required. The consequence of such approximations, however, is the need to implement out-of-market corrections (uneconomic adjustments). This paper presents an overview of out-of-market corrections, an overview of industry related practices that require out-of-market corrections, multiple algorithms that can be used to determine out-of-market corrections, and the various costs and market implications due to out-of-market corrections.