Specifications include, but are not limited to: Maricopa County Department of Public Health (MCDPH) is conducting a vulnerability assessment to understand the health and experience of people who inject drugs. The goals of this assessment are to (1) estimate the number of people who inject drugs in Maricopa County, Arizona, (2) assess the health behaviors, health outcomes, and access to healthcare among people who inject drugs in the county, and (3) identify treatment needs and gaps in availability of services for people who inject drugs, particularly opportunities to reduce the risk of infectious disease transmission. MCDPH is seeking proposals from qualified individuals or organizations to manage field site operations for this county-wide vulnerability assessment. Applicants should have significant experience with project management, ideally related to public health programs or surveys. Ideal candidates will have demonstrated capacity to interact with people who use illicit substances, knowledge of appropriate naloxone administration, and familiarity with local services for people who inject drugs.