The National Academies of Sciences, Engineering, and Medicine's Army Research Laboratory Technical Assessment Board (ARLTAB) provides biennial assessments of the scientific and technical quality of the Army Research Laboratory (ARL). These assessments include the development of findings and recommendations related to the quality of ARL's research, development, and analysis programs. 2019-2020 Assessment of the Army Research Laboratory reviews the following research core competencies of ARL: human sciences, network and information sciences, computational sciences, materials and manufacturing sciences, and propulsion sciences. This biennial report summarizes the findings of the ARLTAB from reviews conducted in 2019 and 2020.