Understanding the True Cost of College Act of 2017 This bill amends the Higher Education Opportunity Act and the Higher Education Act of 1965 to require institutions of higher education to use a standardized financial aid offer form that meets specified requirements. The Department of Education (ED) must develop a standard format for financial aid offer forms based on recommendations from representatives of students, students' families, institutions of higher education, secondary school and postsecondary counselors, and nonprofit consumer groups. The form must include specified details and disclosures regarding: the cost of attendance; aid that does not need to be repaid; the net price that a student or family is estimated to pay; work study assistance; types and amounts of loans, including monthly repayment amounts; sources for additional information; deadlines and the process for accepting financial aid; the academic period covered by the aid; default rates; the percentage of students who have student loans and the median debt at graduation for students; private loans; scholarships; and the terms and conditions of federal financial aid. ED must: (1) test the form with representatives of students, students' families, institutions of higher education, secondary school and postsecondary counselors, and nonprofit consumer groups; and (2) use the results to develop the final form. Each institution of higher education that receives federal financial assistance under the Higher Education Act of 1965 must use the standard form when offering financial aid to students.