Jason A Klein, MD

Dr. Jason Klein is a Clinical Associate Professor of Pediatrics and a pediatric endocrinologist specializing in the care of children, adolescents, and young adults with a wide range of endocrine conditions. His clinical expertise includes disorders of growth, thyroid disease, pubertal development, diabetes, and other hormone-related conditions affecting pediatric and young adult patients.

A major focus of his clinical practice is gender-affirming care for transgender, nonbinary, and gender diverse youth and young adults. He is committed to providing inclusive, respectful, and patient- and family-centered care in a supportive clinical environment.

Prior to joining Stony Brook, Dr. Klein served as the Medical Director of the largest multidisciplinary gender health program in New York State. He also previously served as a Fellowship Program Director, with a strong focus on medical education, mentorship, and training the next generation of pediatric endocrinologists.

Dr. Klein is dedicated to fostering inclusive care, patient safety, and trust within the clinical setting. His interest in pediatric endocrinology was shaped in part by his personal experience living with diabetes, which informs his approach to patient care and advocacy. When not in the hospital or the office, Dr. Klein can be found reading, doing word puzzles, collecting comics, and spending time with his family.