OBJECTIVES: Chlamydia (CT), gonorrhea (GC) and trichomoniasis (TV) screening can be conducted simultaneously on a single sample using nucleic acid amplification testing (NAAT). NAAT has made screening faster and more sensitive. Targeted CT/GC screening has long been supported by clinical guidelines (USPSTF, CDC, and ACOG) and research has shown screening to be cost-effective from a health-system perspective.  Despite this, testing rates are low (estimated at 38% by the CDC).  Here, we explore the clinical and economic impact of increasing adherence to screening guidelines for CT/GC and the introduction of TV screening from a US payer perspective.  METHODS: A decision-tree cost-impact model was developed to compare current screening rates for CT/GC with a hypothetical increase in CT/GC screening uptake and the addition of TV screening in women 15-24yrs. with high-risk sexual behavior.  Model components included testing, treatment, confirmation of eradication, and adverse events for women 15-24.  Inputs were based on published literature. The model examines member cost (excluding partner transmission) and clinical impact of an increase in screening uptake over 1 year. RESULTS: For a hypothetical member population of 5.0M, with a baseline CT/GC/TV prevalence of 4.7/2.2/8.4%, increasing CT/GC screening uptake by 10% and adding simultaneous TV screening has an incremental cost per additional STI detected over a 5-year, 7-year, and lifetime time horizon of $376.18, $272.26, and $30.01, respectively.   The incremental cost per adverse event avoided was $2,239.00, $1,541.86, $182.22, respectively.  Lifetime adverse events avoided (discounted) include: 215 cases of PID, 93 PID-related sequelae, 14 adverse pregnancy outcomes and 0.8 HIV cases. CONCLUSIONS: Given its high prevalence, high rate of asymptomatic cases and the severity of the health consequences, TV should be considered as part of a comprehensive STI screening strategy. Increasing targeted screening for CT/GC/TV could be a cost-effective way of improving women’s health and a health plan’s quality of care.