Group B Streptococcus (GBS) is a leading infectious cause of neonatal morbidity and mortality in the United States. The bacterium, a common colonizer of the maternal genital tract, can infect the fetus during gestation, causing fetal death. GBS also can be acquired by the fetus during passage through the birth canal or after delivery. Infection commonly manifests as meningitis, pneumonia, or sepsis. In 2002, CDC, the American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics issued revised guidelines for prevention of early-onset GBS disease (i.e., in infants aged <7 days). These guidelines recommended universal screening of all pregnant women for rectovaginal GBS colonization at 35-37 weeks' gestation and administration of intrapartum antibiotic prophylaxis (IAP) to carriers. A report published in 2007 indicated that, during 2003-2005, the overall rate of early-onset GBS disease increased, whereas incidence of late-onset GBS disease (i.e., in infants aged 7-89 days) remained stable. This report updates the 2007 report by incorporating 2006 data from the Active Bacterial Core surveillance (ABCs) system. The updated analysis revealed an increase in the overall rate of early-onset GBS disease from 2003 to 2006, driven by an increasing incidence among black term infants. Late-onset GBS disease incidence among black infants, which had increased during 2003-2005, declined in 2006. Continued monitoring is needed to follow trends in early-onset GBS disease among black infants to determine whether additional interventions are warranted.