Pathway for Inclusive Participation of Emerging Leaders and Institutions in the NatSec Enterprise Act of 2020 or the PIPELINE Act of 2020 This bill requires the Department of Defense to establish a federal scholarship-for-service program to recruit, train, and diversify the next generation of national security professionals to meet the needs of federal, state, local, and tribal governments. Specifically, the program must (1) provide scholarships to students who are enrolled in programs of study related to national security at historically Black colleges and universities or at institutions of higher education with at least 50% of total student enrollment from ethnic groups that are underrepresented in the fields of science and engineering, (2) provide scholarship recipients with internship opportunities or other temporary appointments in the federal national security workforce, and (3) prioritize the employment placement of scholarship recipients in the federal government. Additionally, the post-award employment obligations of a scholarship recipient must include three years of work in a position related to national security at a federal, state, local, or tribal agency. A scholarship recipient may fulfill this condition by serving in the Armed Forces. Finally, a scholarship recipient who completes less than the required three years of service must repay the scholarship, or the scholarship must be treated as a Federal Direct Unsubsidized Stafford Loan that is subject to repayment.