Projected Outcomes of Reducing Federal Funding for Syringe Service Programs via Executive Order.

Importance: Syringe service programs (SSPs) deliver evidence-based harm reduction interventions to persons who inject drugs to reduce morbidity and mortality in this population, including syringe exchange, naloxone distribution, linkage to medications for opioid use disorder, and other services. In July 2025, a federal executive order threatened federal support for SSPs in the US. Objective: To estimate the potential long-term outcomes of halting federal funding for SSPs. Design, Setting, and Participants: This decision analytical model study used a closed cohort microsimulation model of the natural history of injection drug use and health outcomes among persons who inject drugs in the US from August 1, 2025, to August 2030. The model was populated with data from the Centers for Disease Control and Prevention's National HIV Behavioral Surveillance system and published data to create representative cohorts of persons who inject drugs nationwide. Exposure: Cases in which total funding for SSPs was reduced by 11% and 80% were modeled. Within each case, 3 potential scenarios related to federal funding disruptions due to an executive order threatening funding for SSPs were modeled: (1) funding disruptions remain in place for 5 years, through August 2030; (2) funding returns to previous levels after 1 year, in August 2026; and (3) funding returns to 100% of previous levels in January 2029. Main Outcomes: The primary outcome was 5-year all-cause and overdose mortality and nonfatal overdoses. Results: In a hypothetical study population of 3 694 500 persons who inject drugs (57.0% male; mean [SD] age, 49.5 [17.5] years), all-cause mortality increased by 0.1% (95% credible interval [CrI], 0-0.2%) to 5.0% (95% CrI, 0-0.8%), overdose mortality increased by 0.2% (95% CrI, -0.1% to 0.4%) to 6.9% (95% CrI, -4.3% to 14.4%), and nonfatal overdoses decreased by 0.1% (95% CrI, -0.2% to 0) to 4.2% (95% CrI, -7.8% to 0.1%) during 5 years across all scenarios. The worst-case scenario, in which there was sustained high levels of service disruption, resulted in 39 600 additional deaths and 15 600 additional overdose deaths among persons who inject drugs in the US. All-cause mortality and overdose mortality increased in most sensitivity analyses. Conclusions and Relevance: In this decision analytical model study estimating the effects of reducing federal funding for SSPs, the findings suggest that mortality will increase among persons who inject drugs during the 5 years after loss of funding. Future studies are needed to understand clinical effects of funding changes.