Abstract
Objectives. To estimate the population size of people who inject drugs (PWID) in the United States in 2022. Methods. We constructed a hybrid estimator, which applied the ratio of nonfatal to fatal overdose among PWID to convert estimated injection-involved overdose deaths to the number of nonfatal overdoses. We divided the number of nonfatal overdose events by the prevalence of nonfatal overdose to generate PWID population size estimates. Results. There were an estimated 2 392 100 (95% confidence interval = 1 323 300, 4 648 100) PWID in 2022, which was 35% lower than the 2018 estimate. Most PWID were male and non-Hispanic White. The US South had the highest number of PWID. Conclusions. Reduced PWID population size may reflect improved data inputs or a true decline in the number of PWID because of high levels of overdose fatality or shifts in routes of drug consumption. These data are essential for determining needs for prevention services and rates of morbidity and mortality among PWID. (Am J Public Health. 2026;116(3):376-379. https://doi.org/10.2105/AJPH.2025.308310).