Neiserria gonorrhoeae and Chlamydia trachomatis are the two most common bacterial sexually transmitted infections (STI) in the United States, affecting an estimated 4 million persons annually at a cost of over $3 billion. After a period of declining morbidity, the prevalence of chlamydial infection is now rising in some areas of the U.S., while rates of gonorrhea are stable, but no longer decreasing. New public health interventions are needed to decrease morbidity from these infections. Improved partner notification and treatment might be such an intervention. Recent randomized controlled trials have demonstrated that expedited partner therapy (EPT), the practice of treating the sex partners of persons with curable STI without their mandatory prior examination by a clinician, can increase the number of partners of persons with gonorrhea or chlamydial infection treated, and can decrease rates of STI reinfection. Study investigators have shown that a public health EPT program can be instituted in a single city to increase partner treatment, but the feasibility of wider scale public health EPT programs has not been established, and the population-level impact and cost-effectiveness of larger EPT programs is unknown. This application proposes a stepped-wedge community-level randomized controlled trial of EPT for gonorrhea and chlamydial infection in Washington (WA) State. A population-based EPT program modeled after one already in place in King County, WA will be instituted in a randomly selected temporal order in 28 health districts in WA State. Free medication will be provided to patients to deliver to their sex partners, and a new case-reporting form will triage public health partner notification assistance to persons at high-risk for not notifying partners. Free medications will be distributed directly to patients via larger clinics in each health district and through a network of commercial pharmacies contracted to participate in the program. The study will assess the impact of EPT on the prevalence of chlamydial infection among women tested in clinics receiving CDC Infertility Prevention Project funding, and on the incidence of reported gonorrhea among women in the state. The proportion of sex partners treated before and after the institution of the EPT program will be estimated based on interviews with a random sample of reported cases: Investigators will evaluate the intervention's cost- effectiveness both from a societal perspective and relative to other publicly funded measures to control gonorrhea and chlamydial infection.