Large language models (LLMs) are increasingly used by patients and caregivers to obtain medical information. In pediatric acute bacterial arthritis, non-guideline-concordant information may be clinically important because timely diagnosis and management are essential. This study evaluated the concordance of LLM-generated responses to parent-oriented reformulations of Pediatric Infectious Diseases Society/Infectious Diseases Society of America (PIDS/IDSA) guideline recommendations.