Skip to main content

Provider Directory

Go to provider search

Ann M. Defnet, MD

  • General Surgery
  • Accepting New Patients
  • 631.938.6999
Gender Female
Facilities Mather General Surgery
Status Active
Medical School Loyola University Chicago Stritch School of Medicine, 2012
Internship/Residency New York University School of Medicine, 2012-2019
General Surgery
Research University of Chicago, 2014-2016
Fellowship Emory University, 2020
Minimally Invasive and Advanced Gastrointestinal Surgery
Special practice interests
  • Minimally invasive surgery
  • Upper gastrointestinal surgery
  • Hiatal hernia surgery
  • Paraesophageal hernia surgery
  • Surgery for acid reflux
  • Surgery for achalasia
  • Inguinal hernia repair
  • Incisional and ventral hernia repair
  • Gallbladder disease
Board certification

American Board of Surgery


Ann M. Defnet, MD is a Board-Certified General Surgeon specializing in Minimally Invasive techniques who has joined Harbor View Medical Services. After her residency in General Surgery at New York University Langone Medical Center and Bellevue Hospital, Dr. Defnet completed fellowship in Minimally Invasive and Advanced Gastrointestinal Surgery at Emory University. She has performed research throughout her training and career, including a two-year Research Fellowship at the University of Chicago. She has authored many peer-reviewed publications, as well as presented nationally regarding minimally invasive surgical techniques and outcomes.

Dr. Defnet specializes in upper gastrointestinal surgery utilizing minimally invasive approaches including hiatal and paraesophageal hernia surgery, surgery for acid reflux, and surgery for achalasia. She also specializes in laparoscopic and robotic approaches to general surgery, including inguinal hernia repair, incisional and ventral hernia repair, and gallbladder disease. She enjoys using the robotic platform to help carefully selected patients recover more quickly from surgery, and has won an award for her robotic skills. She prides herself on truly listening to her patients, and working with the other doctors in her patient’s care team to provide complete care.

Although a Midwest native and avid Green Bay Packer fan, Dr. Defnet is excited to be practicing in beautiful Long Island. She enjoys cooking and baking, and is hoping to one day raise chickens.