What patients are saying
Overall rating
4.81
Average wait time
4.38
Bedside manner
4.90
“I'm definitely going to go back and I do recommend this doctor to all, everything was quick, easy, and a hassle-free from beginning to end. Assistance and secretarial persons explained in detail, as well as got all my information prior to visit, and contact reminders were on point, as well as answered all questions and inquiries.”
Damon Z.April 2, 2026
“Very clean, comfortable office. Staff was friendly and efficient. Doctor was engaging, informative and thorough. I feel very comfortable under his care. ”
Ellen S.April 1, 2026
About Dr. Kenneth Zierer
Dr. Kenneth G. Zierer is a gastroenterologist at Gastroenterology Associates of New Jersey. He is triple board certified in internal medicine, and gastroenterology by the American Board of Internal Medicine.
Dr. Zierer completed a fellowship in hepatology, a combined residency and internship program for internal medicine and pediatrics as well as his medical degree from Rutgers New Jersey Medical School in Newark, NJ. In addition, he received his bachelor’s degree from George Washington University in Washington, D.C.
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In-network insurances
99% of patients have successfully booked with these insurances
Aetna
BlueCross BlueShield
Cigna
Medicare
UnitedHealthcare
UnitedHealthcare Oxford
Areas of expertise
This doctor's experience enhances their expertise in similar cases. Below are the conditions or surgeries they treat most frequently.
Acid reflux
Irritable Bowel Syndrome (IBS)
Upper GI endoscopy
Acute gastrointestinal bleeding
Colonoscopy
Acid reflux
Irritable Bowel Syndrome (IBS)
Upper GI endoscopy
Acute gastrointestinal bleeding
Office locations
Gastroenterology Associates of NJ (1 of 2)
925 Clifton Ave, Suite 101, Clifton, NJ 07013
Gastroenterology Associates of NJ (2 of 2)
71 Union Ave, Suite #201, Rutherford, NJ 07070
1 of 2
Education and background
Practice names
Board certifications
- Gastroenterology (American Board of Internal Medicine)
- American Board of Internal Medicine
Education and training
- Medical School - Rutgers University, Doctor of Medicine
- Rutgers University, Fellowship in Gastroenterology and Hepatology
- The George Washington University (Bachelor's)
- Rutgers University, Residency in Internal Medicine
Awards and publications
- Castle Connolly Top Doctor
- Dr. Kenneth Zierer was Awarded Castle Connolly Top Doctors 2023
- Dr. Kenneth Zierer was Awarded Bergen County's Top Doctors 2023
Languages spoken
- English
Provider's gender
Male
NPI number
1417978883
Patient reviews
All reviews have been submitted by patients after interacting with the practice.
Overall rating
4.81
Wait time
4.38
Bedside manner
4.90
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
106 reviews
Most relevant
This was my first time seeing Dr. Zierer. He was very attentive and patient with me. I would recommend him to other patient
Less than 6 months agoMaks S.Verified patient
Very easy to schedule. The staff made it easy once I was there. I was provided detailed instructions for next appointment.
May 16, 2025louis J.Verified patient
Very satisfied, easy to get an appt. Especially happy I had results before leaving the colonoscopy/endoscopy appt.
Less than 1 year agoLS
He’s was great the way he explained himself and what I need to do I recommend people to come see this doctor.
May 20, 2025Salomon S.Verified patient
Generic visit. The doctor touched on everything I might have any questions on kept me very informed.
Less than 1 year agoET
Always has an answer to my questions, excellent bedside manners. The MA's are also very sweet; kind.
Less than 1 year agoJO
Great facility and caring staff made visit smooth & pleasant Dr. Zierer was wonderful. Thank you.
Less than 1 year agoHL
A professiinal and friendly manner. Never rushed and listened to whatbi had to say.
August 28, 2025Jason H.Verified patient
Quick and easy. Dr. Zierer has a pleasant demeanor. Sometimes the wait is a little long.
Less than 1 year agoEK
He is great physician, he has listened all my concerns and answered all my questions.
Less than 1 year agoSD
Excellent, everyone was so nice and helpful. The doctor explained everything to me!
Less than 1 year agoHB
experience was great!!!!! might of fat fingered 1st question but i give all stars
April 30, 2025Michael P.Verified patient
Dr was very knowledge and his diagnosis was logical.
December 24, 2025Michael J.Verified patient
Explained everything and I was able to see a doctor within a week.
June 26, 2025Lori S.Verified patient
Felt the doctor truly listened. Was able to get an appointment quickly.
April 7, 2025Lori S.Verified patient
Great doctor, detailed and professional explanation of my condition.
March 4, 2025Taisiya S.Verified patient
The first visit went well! Polite and respectful staff.
Less than 1 year agoER
Dr was very nice
Explained the procedure very well
March 28, 2025Martha D.Verified patient
I'm definitely going to go back and I do recommend this doctor to all, everything was quick, easy, and a hassle-free from beginning to end. Assistance and secretarial persons explained in detail, as well as got all my information prior to visit, and contact reminders were on point, as well as answered all questions and inquiries.
April 2, 2026Damon Z.Verified patient
Very clean, comfortable office. Staff was friendly and efficient. Doctor was engaging, informative and thorough. I feel very comfortable under his care.
April 1, 2026Ellen S.Verified patient
Great doctor very educated and easy to talk to! Wait time was exhausting it was well over an hour until I saw the doctor and I was on time to the apt.
Less than 1 month agoInitials hidden
I have been with Dr.Zieirer for long time!
Less than 3 months agoInitials hidden
I arrived significant ly early as I had conxised the correct time and they accommodated me with grace and professionalism. The doctor was timely, interested and spent a very generous amount of time with me. An overall excellent experience.
December 18, 2025Robert H.Verified patient
Dr. Frier appeared knowledgeable and was able to discuss my issue. The staff was very helpful. Wait time was rather long (35 minutes).
Less than 6 months agoDD
Very very good.
Less than 6 months agoCT
Great doctor, and friendly staff.
October 2, 2025Elisa C.Verified patient
Great service with a lot patience friendly
September 15, 2025Anita P.Verified patient
Dr Zierer is the kindest, most compassionate doctor. He spends a lot of time with you, never rushes you. He really listens to you and genuinely wants to get to the heart of the problem. I’ve been coming to see Dr Zierer for over 20 years and have never been disappointed!
September 2, 2025Nora R.Verified patient
Dr. Zierer was great! He made the consultation & procedure very relaxed, easing any anxiety I may have had with having a colonoscopy. I would definitely go back to him for my 10-year check-up.
August 28, 2025Tan N.Verified patient
Dr. Zierer is the best. He is very patient with all of my questions and takes the time to explain and talk through all of my concerns. I cannot recommend him enough!
August 26, 2025Nick P.Verified patient
Every appointment is very long, wait times for very short conversations, and at my consultation, I waited 2 hours before even being seen.
Less than 1 year agoInitials hidden
I was waiting for over three hours, don’t go
August 15, 2025Lohanny C.Verified patient
Only negative I have was the time waiting to be seen, doctor was otherwise responsive and didn’t feel rushed once I was seen. Office and medical staff were all pleasant, and was able to get a same day appointment on Zocdoc.
Less than 1 year agoInitials hidden
Good. Yes
August 7, 2025Jay D.Verified patient
He is very thorough, friendly and kind. Asked a lot of great questions and explained each of the possible causes clearly. Also really appreciate how attentive he and the office is.
August 6, 2025Christina J.Verified patient
The experience was helpful.
August 5, 2025Antione S.Verified patient
Doctor and his assistant were wonderful! Very friendly, funny and great listeners! It was an enjoyable experience. Took all of my nervousness away!
August 4, 2025Initials hidden
It was great. friendly
July 10, 2025Jeff M.Verified patient
I would definitely go back, Dr. Zeier is the best GI doctor I have seen, he is so honest, trustworthy doctor I have even seen, his office staff is wonderful, never had a problem with any of them. Office is very clean, trust myself with the office. Everything about the staff, office and especially the doctor is just great.
June 20, 2025Theresa C.Verified patient
Always helpful.
Less than 1 year agoDA
Very good.
Less than 1 year agoZA
My visits are always positive, & I am well taken care of. The staff & doctors are always courteous professional & take the time to listen to my issues/ concerns. Highly recommend them. Have been a patient for many years. Dr. Zierer is highly knowledgeable & a terrific doctor.
Less than 1 year agoMA
Muy bueno por el lugar doctor y facieltae.
Less than 1 year agoJM
FM. mebiento muy complacida deocler comocido, a kemikencia did my quecido Doctor pues para muykas sido lo major y sugo el Dr. que dios le boudigai scarifire so fuero.
Less than 1 year agoMF
The initial greeting was immediate and very friendly. Each person that I interacted with was polite and professional. Dr. Zierer was very friendly and very detailed in narrowing down what was bothering me.
Less than 1 year agoLJ
Great service.
Less than 1 year agoCD
O.K
Less than 1 year agoWM
Straight forward and simple, good communication.
Less than 1 year agoSH
Recibo exelentes atscions una veg me presento en el consultonio. Todo el personal es muy atento y enable. En el tiempo que recibo atencion of Dr. es bueue y guedo muy comforme con sus atencions.
Less than 1 year agoAF
Great.
Less than 1 year agoMS
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How soon can I make an appointment with Dr. Kenneth Zierer?
Generally, Dr. Kenneth Zierer has appointments available on Zocdoc within 1 week. You can see Dr. Zierer's earliest availability on Zocdoc and make an appointment online.
Is Dr. Kenneth Zierer accepting new patients?
Dr. Kenneth Zierer generally accepts new patients on Zocdoc. You can see Dr. Zierer's earliest availability on Zocdoc and schedule an appointment online.
Does Dr. Kenneth Zierer accept my insurance?
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Can I make an appointment with Dr. Kenneth Zierer online?
Yes, you can make an appointment online with Dr. Zierer using Zocdoc. It’s simple, secure, and free.
What practice does Dr. Kenneth Zierer work with?
Dr. Kenneth Zierer works with Gastroenterology Associates of NJ.
Where is Dr. Kenneth Zierer's office located?
Dr. Kenneth Zierer has 2 office locations, including in Rutherford and Clifton, view full addresses on Dr. Zierer's profile.
Which board certifications does Dr. Kenneth Zierer have?
Dr. Kenneth Zierer is certified by Gastroenterology (American Board of Internal Medicine) and American Board of Internal Medicine.
What are common reasons for patients to see Dr. Kenneth Zierer?
Dr. Kenneth Zierer frequently sees patients for Abdominal Pain, Colonoscopy, Gastroenterology Consultation, Hemorrhoids, and Weight Loss Consultation. You can see other visit reasons for Dr. Kenneth Zierer on their profile.
What languages does Dr. Kenneth Zierer speak?
Dr. Kenneth Zierer speaks English.
How do patients rate Dr. Kenneth Zierer in reviews?
105 patients have reviewed Dr. Kenneth Zierer. The overall rating for this doctor is 4.81/5. They have a 4.91/5 rating for bedside manner and a 4.4/5 rating for wait time. You can read individual reviews and ratings on their profile.