Affordable College Textbook Act This bill directs the Department of Education (ED) to make grants to institutions of higher education (IHEs) to support projects that expand the use of open textbooks in order to achieve savings for students while maintaining or improving instruction and student learning outcomes. An open textbook is an educational resource that either resides in the public domain or has been released under an intellectual license that permits its free use, reuse, modification, and sharing with others.