Hepatitis B (HBV) vaccination coverage remains low among drug users. In 1997, ACIP made hepatitis B vaccine available for persons aged 0–18 years and many states began requiring HBV vaccination for entry into middle school; these programs might affect HBV vaccination and infection rates in younger DUs. We were interested in determining correlates of immunization among younger (<25 years) and older (25 and older) DUs. Methods: A community-based sample of 1,211 heroin, crack, and cocaine users 18 or older was recruited from Harlem and the Bronx. We assessed previous HBV vaccination and infection and correlates using bivariate analyses. Results: The sample was predominantly male (74.0%), aged ≥25 years (67.1%) and Hispanic (59.9%). In terms of socioeconomic status, 57.1% had less than a high school education, 84.5% had been homeless in their lifetime, and 48.0% had an illegal main income source. Among 399 DUs younger than 25 years of age, 30% demonstrated serological evidence of previous vaccination, 49.9% were susceptible to HBV at baseline, and 20% showed evidence of infection. In our model, previous HBV infection and vaccination status were associated with being 22 years old or younger (AOR = 1.40 and 1.66). Compared to susceptible individuals, those vaccinated were significantly less likely to be born in other countries (AOR = 0.50). Among 812 DUs 25 and older, 10.6% demonstrated serological evidence of previous vaccination, 59.2% were susceptible to HBV at baseline, and 30.2% showed evidence of infection. Conclusion: Existing interventions to increase HBV vaccination among adolescents should target high risk groups.