This report provides information about the FY2018 budget request for the Department of Health and Human Services (HHS). It begins by reviewing the department’s mission and structure. This is followed by an overview of the total FY2018 request for the department. Next, the report discusses the concept of the HHS budget as a whole, compared to funding provided to HHS through the annual appropriations process. This distinction is important because certain amounts shown in FY2018 HHS budget materials (including amounts for prior years) will not match amounts provided to HHS by annual appropriations acts (and displayed in accompanying congressional documents), because they take into account a broader set of budgetary resources. The report concludes with a breakdown of the HHS request by agency, along with additional HHS resources that provide further information on the request. A table of key policy staff is included at the end of the report.