BackgroundIn recent years, both methamphetamine use and STIs have been on the rise in the USA. In this analysis, we sought to ascertain whether the risk of STIs and HIV among methamphetamine users was moderated on the basis of participation in substance use treatment programmes.MethodsData came from the National Survey on Drug Use and Health, 2015–2019. Among adult participants, survey-weighted logistic regression analyses were used to assess the relationship between past year methamphetamine use and risk of HIV and STIs, stratified by methamphetamine treatment utilisation and adjusted for demographic and other risk factors.ResultsAmong participants in the analytic sample (n=210 392), 1862 (0.9%) reported past year methamphetamine use, 566 (0.3%) reported receiving treatment for its use, 5471 (2.6%) tested positive for any STI in the past year and 395 (0.2%) for HIV ever in their lifetime. Past year methamphetamine use was associated with increased risk of STIs among those who did not receive treatment (adjusted OR=3.628; 95% CI 2.75 to 4.92). Significant moderation was also present between past-year methamphetamine use, risk of STI, and substance use treatment.ConclusionIn this analysis, we demonstrated a strong relationship between methamphetamine use and risk of STIs that differed based on receipt of substance use treatment. These findings suggested that integrated STI and substance use treatment programmes may yield substantial public health benefits.