To help "assure that all children with disabilities have available to them ... a free appropriate public education which emphasizes special education and related services designed to meet their unique needs," 20 U. S. C. §1400(c), the Individuals with Disabilities Education Act (IDEA) authorizes federal financial assistance to States that agree to provide such children with special education and "related services," as defined in §1401(a)(17). Respondent Garret F., a student in petitioner school district (District), is wheelchair-bound and ventilator dependent; he therefore requires, in part, a responsible individual nearby to attend to certain physical needs during the school day. The District declined to accept financial responsibility for the services Garret needs, believing that it was not legally obligated to provide continuous one-on-one nursing care. At an Iowa Department of Education hearing, an Administrative Law Judge concluded that the IDEA required the