In 2017, the Council of State and Territorial Epidemiologists performed its sixth periodic Epidemiology Capacity Assessment, a national assessment that evaluates trends in workforce size, funding, and epidemiology capacity among state health departments. A standardized web-based questionnaire was sent to the state epidemiologist in the 50 states, the District of Columbia (DC), and the U.S. territories and the Federated States of Micronesia inquiring about the number of current and optimal epidemiologist positions; sources of epidemiology activity and personnel funding; and each department's self-perceived capacity to lead activities, provide subject matter expertise, and obtain and manage resources for the four Essential Public Health Services (EPHS)* most closely linked to epidemiology. From 2013 to 2017, the number of state health department epidemiologists† increased 22%, from 2,752 to 3,369, the greatest number of workers since the first full Epidemiology Capacity Assessment enumeration in 2004. The federal government provided most (77%) of the funding for epidemiologic activities and personnel. Substantial to full capacity (50%-100%) was highest for investigating health problems (92% of health departments) and monitoring health status (84%), whereas capacity for evaluating effectiveness (39%) and applied research (29%) was considerably lower. An estimated additional 1,200 epidemiologists are needed to reach full capacity to conduct the four EPHS. Additional resources might be needed to ensure that state health department epidemiologists possess the specialized skills to deliver EPHS, particularly in evaluation and applied epidemiologic research.