EPA anticipates awarding approximately $400 million in Clean School Bus (CSB) funding under this Notice of Funding Oppotunity (NOFO), subject to the availability of funds, the quantity and quality of applications received, and other applicable considerations. To ensure a healthy grant competition, this NOFO includes two sub-programs, one for school district and Tribal applicants (School District Sub-program) and one for thirdparty applicants (Third-Party Sub-program) to serve at least four school district beneficiaries. EPA is providing two separate competitions under this single NOFO to address the unique needs and concerns of diverse recipients and encourage participation in the CSB grants program.