Mount Diablo Unified School District (MDUSD) is a public school district in Contra Costa County, California. It currently operates 29 elementary schools, 10 middle schools, and six high schools, with 7 alternative school programs and an adult education program. MDUSD is one of the largest school districts in the state of California, with over 56 school sites and a budget of approximately $270,000,000. The district has over 36,000 K-12 students, over 20,000 adult education students, and over 3,500 employees, including over 2,000 certificated educators.