The United States is the largest provider of food aid in the world, accounting for over half of all global food aid supplies intended to alleviate hunger. Since the 2002 reauthorization of the Farm Bill, Congress has appropriated an average of $2 billion per year for U.S. food aid programs, which delivered an average of 4 million metric tons of agricultural commodities per year. Despite growing demand for food aid, rising business and transportation costs have contributed to a 43-percent decline in average tonnages delivered over the last 5 years. For the largest U.S. food aid program, these costs represent approximately 65 percent of total food aid expenditures, highlighting the need to maximize the efficiency and effectiveness of food aid. To inform Congress as it reauthorizes the 2007 Farm Bill, GAO examined some key challenges to the (1) efficiency of delivery and (2) effective monitoring of U.S. food aid.