Building Indigenous STEM Professionals Act This bill expands the grant program for science, technology, engineering, and mathematics (STEM) programs that benefit Native American students. Under current law, this program only applies to programs that benefit Alaska Natives and Native Hawaiians. The bill expands grant eligibility to include programs that benefit American Indians. Additionally, the bill authorizes grants under the program for the creation of new programs for the development of Native American STEM professionals. The bill also revises how programs are prioritized for awarding grants. The bill gives priority to programs in which 70% or more of the participants are Native Americans.