IMPORTANCE Perinatal transmission of human immunodeficiency virus (HIV) can be reduced through services including antiretroviral treatment and prophylaxis. Data on the national incidence of perinatal HIV transmission and missed prevention opportunities are needed to monitor progress toward elimination of mother-to-child HIV transmission. OBJECTIVE To estimate the number of perinatal HIV cases among infants born in the United States. DESIGN, SETTING, AND PARTICIPANTS Data were obtained from the National HIV Surveillance System on infants with HIV born in the United States (including the District of Columbia) and their mothers between 2002 and 2013 (reported through December 31, 2015). Estimates were adjusted for delay in diagnosis and reporting by weighting each reported case based on a model incorporating time from birth to diagnosis and report. Analysis was performed from April 1 to August 15, 2016. EXPOSURES Maternal HIV infection and antiretroviral medication, including maternal receipt prenatally or during labor/delivery and infant receipt postnatally. MAIN OUTCOMES AND MEASURES Diagnosis of perinatally acquired HIV infection in infants born in the United States. Infant and maternal characteristics, including receipt of perinatal HIV testing, treatment, and prophylaxis. RESULTS The estimated annual number of perinatally infected infants born in the United States decreased from 216 (95% CI, 206-230) in 2002 to 69 (95% CI, 60-83) in 2013. Among perinatally HIV-infected children born in 2002-2013, 836 (63.0%) of the mothers identified as black or African American and 243 (18.3%) as Hispanic or Latino. A total of 236 (37.5%) of the mothers had HIV infection diagnosed before pregnancy in 2002-2005 compared with 120 (51.5%) in 2010-2013; the proportion of mother-infant pairs receiving all 3 recommended arms of antiretroviral prophylaxis or treatment (prenatal, intrapartum, and postnatal) was 22.