What patients are saying
Overall rating
4.96
Average wait time
4.79
Bedside manner
5.00
“Dr Haas had an amazing bedside manner and immediately made my daughter feel comfortable enough to speak about her situation on her own. For a small child that’s a pretty big deal. After we left, she told me that she knew he was a great doctor and could definitely help her. She was absolutely right, his suggestions and diagnosis was spot on. I couldn’t be more impressed. Highly recommended.”
Avianna P.August 8, 2026
“Dr. Haas was great with my daughter. She is six, and he was able to communicate clearly and effectively with her to get the information he needed. He also provided us with a comprehensive care plan and scheduled follow-ups to ensure we are on the right track to helping her feel well again. ”
Ariella D.March 23, 2026
About Dr. Leonard Haas
Dr. Leonard A. Haas is a pediatric gastroenterologist committed to providing excellent care to patients and their families. Throughout his medical career, he has been guided by the core value of always putting the needs of his patients first. Dr. Haas utilizes his excellent education and experience in medicine, research, and teaching in his approach to patient care by dedicating himself to meeting each patient’s unique needs, communicating effectively, educating patients and their families, and fostering shared decision-making with attentive listening and collaboration.
Dr. Haas received his medical degree from the Mayo Clinic School of Medicine in Rochester, Minnesota. He completed his Pediatric internship and residency at New York Presbyterian-Weill Cornell Medical Center and his fellowship in Pediatric Gastroenterology, Hepatology, and Nutrition at Johns Hopkins Hospital in Baltimore, Maryland.
Dr. Haas specializes in caring for children and adolescents with gastrointestinal problems and liver disorders, such as inflammatory bowel disease, disorders of brain-gut interaction, nutrition issues, abdominal pain, constipation, gastroesophageal reflux, feeding problems, pancreatic diseases, among others. He performs endoscopies, colonoscopies, and other advanced procedures.
Dr. Haas is a member of the North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN), American Gastroenterological Association (AGA), and American Academy of Pediatrics (AAP), Sigma Xi, the Scientific Research Society, and the Crohn’s and Colitis Foundation. He has contributed to advancements in medicine through his extensive list of peer-reviewed publications and poster presentations at national and international conferences. His research interests involve utilizing new technology and computer science techniques to enhance patient care and create new tools to increase efficiency and ensure best practices.
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Popular visit reasons
Digestive Problem
Gastroscopy
Pediatric Acid Reflux / Heartburn
Pediatric Gastroenterology Consultation
Pediatric Gastroenterology Follow Up
Pediatric Gastrointestinal Problem
Pediatric Gastroscopy
Stomach Pain
Digestive Problem
Gastroscopy
Pediatric Acid Reflux / Heartburn
Pediatric Gastroenterology Consultation
Office locations
Optum Medical Care, P.C. (1 of 2)
165 N Village Ave, Ste 215, Rockville Centre, NY 11570
Optum Medical Care P.C. - 2800 Marcus Ave (2 of 2)
2800 Marcus Ave, New Hyde Park, NY 11042
1 of 2
Education and background
Practice names
Board certifications
- American Board of Pediatrics
Education and training
- Medical School - Mayo Clinic, Doctor of Medicine
- NewYork-Presbyterian / Weill Cornell Medical Center, Internship in Pediatrics
- NewYork-Presbyterian / Weill Cornell Medical Center, Residency in Pediatrics
- The Johns Hopkins Hospital, Fellowship in Pediatric Gastroenterology, Hepatology, and Nutrition
Professional memberships
- American Gastroenterological Association
- The American Academy of Pediatrics
Languages spoken
- English
Provider's gender
Male
NPI number
1073019584
Patient reviews
All reviews have been submitted by patients after interacting with the practice.
Overall rating
4.96
Wait time
4.79
Bedside manner
5.00
Your trust is our top concern, so providers can't pay to alter or remove reviews. We also don't publish reviews that contain any private patient health information. Learn more here
50 reviews
Most relevant
Really good bedside manner with my child. Listened and emphasized with my concerns. Very knowledgeable and friendly
October 22, 2024Gina A.Verified patient
Lo recomiendo 100% un dr. muy atento con las preguntas y su asistente me encanto como nos trato.????
April 9, 2025Esther R.Verified patient
Great doctor! Listened and validated my daughter’s concerns. Knowledgeable, professional and kind
September 24, 2024Initials hidden
Seen right away. Was great with kids. Friendly office.
April 9, 2025Initials hidden
Dr Haas had an amazing bedside manner and immediately made my daughter feel comfortable enough to speak about her situation on her own. For a small child that’s a pretty big deal. After we left, she told me that she knew he was a great doctor and could definitely help her. She was absolutely right, his suggestions and diagnosis was spot on. I couldn’t be more impressed. Highly recommended.
August 8, 2026Avianna P.Verified patient
Dr. Haas was great with my daughter. She is six, and he was able to communicate clearly and effectively with her to get the information he needed. He also provided us with a comprehensive care plan and scheduled follow-ups to ensure we are on the right track to helping her feel well again.
March 23, 2026Ariella D.Verified patient
Dr. Haas beside manners was great. He kept engaging with my son to find information about his issues. He asked alot of questions and reviewed his chart so he could give a proper diagnosis of what my son is going through.
March 17, 2026Initials hidden
Lets start with the office staff . WOW. So friendly...every person. It was honestly refreshing to talk with people that were happy to be there. The doc...Dr. Haas....one of the best pediatric docs I've seen. So friendly, patient, great way with kids from the way he spoke to my daughter to the way he examined her. Can't say enough.....HIGHLY RECOMMENDED.
August 13, 2025Dylan R.Verified patient
Dr. Haas was so thorough and took his time with my son. He ran a ton of tests and was extremely detailed in his explanations. He listened and asked good questions and engaged my son in conversation between medical questions.
July 3, 2025Jessica L.Verified patient
Wonderful experience! Dr. Haas was thoughtful, considerate, and excellent listener and patient with my son. He immediately connected with my son by finding a common interest to ease his nerves. After that my son was able to express his gastro issues. Dr. Haas came up with a preliminary diagnosis and plan that we felt very comfortable with and set us up to return in 2 weeks. He is kind, friendly, knowledgeable and a calming presence. As a mom, I appreciate his manner and positive energy. I highly recommend him to every parent concerned with GI issues for their child. I’m grateful to have found him.
February 18, 2025Raymond S.Verified patient
Dr Haas listened to my teen dtr. He asked us both questions. I felt he was very thorough and genuinely concerned about her problems.
February 12, 2025Jeanette R.Verified patient
Excellent Dr! Dr Haas made us feel very comfortable and addressed our concerns straight away! Highly recommend and look forward to seeing him again!
February 3, 2025Esaam H.Verified patient
Dr. Haas is compassionate and genuine in our visits. Realistic and helpful, down to earth in conversation with my teen daughter about her digestive progress.
January 29, 2025Stephanie H.Verified patient
Dr. Haas was wonderful with my teen daughter and handled uncomfortable GI convo with dignity and respect, not speaking over her but involving her in the visit.
December 30, 2024Stephanie H.Verified patient
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Generally, Dr. Leonard Haas has appointments available on Zocdoc within 1 week. You can see Dr. Haas's earliest availability on Zocdoc and make an appointment online.
Is Dr. Leonard Haas accepting new patients?
Dr. Leonard Haas generally accepts new patients on Zocdoc. You can see Dr. Haas's earliest availability on Zocdoc and schedule an appointment online.
Does Dr. Leonard Haas accept my insurance?
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Can I make an appointment with Dr. Leonard Haas online?
Yes, you can make an appointment online with Dr. Haas using Zocdoc. It’s simple, secure, and free.
What practice does Dr. Leonard Haas work with?
Dr. Leonard Haas works with Optum Medical Care, P.C..
Where is Dr. Leonard Haas's office located?
Dr. Leonard Haas has 2 office locations, including in New Hyde Park and Rockville Centre, view full addresses on Dr. Haas's profile.
Which board certifications does Dr. Leonard Haas have?
Dr. Leonard Haas is certified by American Board of Pediatrics.
What are common reasons for patients to see Dr. Leonard Haas?
Dr. Leonard Haas frequently sees patients for Digestive Problem, Gastroscopy, Pediatric Gastroenterology Consultation, Pediatric Gastrointestinal Problem, and Stomach Pain. You can see other visit reasons for Dr. Leonard Haas on their profile.
What languages does Dr. Leonard Haas speak?
Dr. Leonard Haas speaks English.
How do patients rate Dr. Leonard Haas in reviews?
52 patients have reviewed Dr. Leonard Haas. The overall rating for this doctor is 4.96/5. They have a 5/5 rating for bedside manner and a 4.79/5 rating for wait time. You can read individual reviews and ratings on their profile.