This report discusses the FY2019 appropriations request for the Department of Health and Human Services. The report begins by reviewing the department's mission and structure. Next, the report offers a brief explanation of the conventions used for the FY2018 estimates and FY2019 request levels in the budget documents released by the HHS and the Office of Management and Budget (OMB). The report also discusses the concept of the HHS budget as a whole, in comparison to how funding is provided to HHS through the annual appropriations process. 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 CRS key policy staff is included at the end of the report.