Children in U.S. military families may transfer schools nine times, on average, before they graduate from high school. These moves may be especially challenging for children with disabilities and their families, as special education services provided under the Individuals with Disabilities Education Act--the primary federal special education law--must be reestablished with each new school. Sections 589G and 589H of the William M. (Mac) Thornberry National Defense Authorization Act (NDAA) for Fiscal Year 2021 include provisions for GAO to examine and report on a range of military children's education issues. This report provides information on two broad topic areas: (1) DOD programs that offer support to military families having children with disabilities; and (2) DOD programs that support school districts that serve military families. GAO analyzed data on DOD Impact Aid programs. GAO also (1) held four discussion groups with DOD officials, representing all four military services, responsible for providing support to military families with children with disabilities; (2) interviewed officials at six school districts, selected based on their proximity to military installations and eligibility for certain federal funds; and (3) interviewed officials from DOD and representatives of national advocacy groups for military children. GAO also reviewed relevant federal laws, regulations, and guidance.