The Assistant Secretary for Planning and Evaluation (ASPE) is the principal advisor to the Secretary of the U.S. Department of Health and Human Services (HHS) on policy development, and is responsible for major activities in policy coordination, legislation development, strategic planning, policy research, evaluation, and economic analysis. In this role, ASPE, through its Office of Science and Data Policy (OSDP), is responsible for developing the HHS Strategic Plan and the HHS Evidence-Building Plan (the plans) every four years.