Barry Goldwater Scholarship and Excellence in Education Modernization Act This bill revises the Barry Goldwater Scholarship and Excellence in Education Program. Among other changes, the bill (1) expands program eligibility to undergraduate students who are noncitizens; (2) allows the related foundation to award research internships to outstanding undergraduate students who intend to pursue careers in the natural sciences, engineering, and mathematics; (3) allows students who are awarded such research internships to receive stipends; and (4) authorizes the Department of the Treasury to invest related fund assets in securities other than U.S. public debt securities under certain circumstances.