Administration and Faculty

Hajoon Chun, MD, FACOG


Director of Maternal Fetal Medicine

Dr. Hajoon Chun has been the Director of Maternal Fetal Medicine at Flushing Hospital Medical Center since 2001. After graduating from Tufts Medical School and finishing his residency at New York Downtown Hospital, he completed his MFM fellowship at Mount Sinai Medical Center. Dr. Chun is well respected in the community and has an extremely busy practice, yearly seeing over 10,000 patients and performing over 600 amniocenteses.  In addition to overseeing the department, Dr. Chun continues to play an immense part in resident education.  He is dedicated to supporting the residency and working with the administration to ensure that education is always a priority. 


Justin To, MD, FACOG

Program Director

Director of Minimally Invasive Surgery

Dr. To is a native of Harrison, NY. After attending medical school at Stony Brook University School of Medicine, he completed both his OB/GYN residency training and his Minimally Invasive Gynecologic Surgery Fellowship at Montefiore Medical Center/Albert Einstein College of Medicine. He stayed as a core faculty member and held multiple roles, including Fellowship Site Director for Minimally Invasive Gynecologic Surgery, Assistant Professor, and Associate Clerkship Director.  He brings his passion for both education and clinical medicine to Flushing, and is dedicated to continual improvement of the program.


Ervin Rene Riano-Marin, MD

Associate Program Director

Dr. Riano was raised in Bogota, Colombia.  After graduating from Pontificia Universidad Javeriana Medical School, he spent time performing research at the Oregon Health and Science University in Portland, OR before coming to Flushing. He is a proud graduate of the Flushing Hospital Medical Center OB-GYN Residency Program. He is also a member of the APGO Surgical Education Scholar Program, and has multiple publications.  He has vast experience in both obstetrics and gynecology, with expertise in minimally invasive surgery methods. Dr. Riano has been the bed rock of the residency program and is excited to bring even further improvements to the curriculum.


Alejandro Alcaide, MD, FACOG

Director of Gynecology

Dr. Alcaide graduated from Penn State University Medical School and completed residency at Brookdale Hospital in Brooklyn, NY. He has been an integral part of Flushing Hospital Medical Center for over 20 years and plays a large role in resident education and training.  Particularly, he has extensive experience and expertise in minimally invasive surgery and urogynecology.  He is an extremely high-volume robotic surgeon, and is enthusiastic in teaching his skills to the residents.