The document summarizes changes to CDC guidelines for prevention of early-onset group B streptococcal (GBS) disease. Key changes include: expanded laboratory detection options for GBS; revised thresholds for reporting GBS in urine cultures; clarified definitions of adequate antibiotic prophylaxis and high risk for anaphylaxis; and adjustments to neonatal management algorithms to reduce unnecessary evaluations. Guidelines emphasize using cefazolin over clindamycin or vancomycin when possible for penicillin-allergic women.