BACKGROUND: Sexual transmission of hepatitis B virus (HBV) is common in the United States. In 2008, an estimated 50% of HBV infections were attributed to sexual transmission. Among 21,600 acute infections that occurred in 2018, the proportion attributable to sexual transmissions is unknown. METHODS: Objectives of this study were to estimate incidence and prevalence of hepatitis B attributable to sexual transmission among the US population 15 years and older for 2013 to 2018. Incidence estimates were calculated for confirmed cases submitted to Centers for Disease Control and Prevention from 14 states. A hierarchical algorithm defining sexually transmitted acute HBV infections as the absence of injection drug use among persons reporting sexual risk factors was applied to determine proportion of hepatitis B infections attributable to sexual transmission nationally. National Health and Nutrition Examination Survey public use data files were analyzed to calculate prevalence estimates of hepatitis B among US households and proportion attributed to sexual transmission was conservatively determined for HBV-infected non-US-born Americans who migrated from HBV endemic countries. RESULTS: During 2013 to 2018, an estimated 47,000 (95% confidence interval [CI], 27,000-116,000) or 38.2% of acute HBV infections in the United States were attributable to sexual transmission. During 2013 to 2018, among the US noninstitutionalized population, an estimated 817,000 (95% CI, 613,000-1,100,000) persons 15 years and older were living with hepatitis B, with an estimated 103,000 (95% CI, 89,000-118,000) infections or 12.6% attributable to sexual transmission. CONCLUSIONS: These findings provide evidence sexually transmitted HBV infections remain a public health problem and underscore the importance of interventions to improve vaccination among at-risk populations.