Social Determinants Accelerator Act of 2019 This bill establishes the Social Determinants Accelerator Interagency Council and provides funds for the council to (1) assist the Department of Health and Human Services (HHS) in awarding specified grants, (2) increase coordination among health and social service programs, and (3) provide program evaluation guidance and technical assistance to increase the impact of social service programs. Specifically, the bill provides funds for HHS to award up to 25 grants to state, local, or tribal health or human services agencies for the development of social determinants accelerator plans that address at least one health and one social outcome for a specified target population.