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Department Endocrinology, Diabetes and Metabolism
Primary Location Cleveland Clinic Main Campus
Type of Doctor Both Adults and Children & Adolescents
Languages English
Surgeon No
Cleveland Clinic Main Campus
Primary Location

Cleveland Clinic Main Campus


Additional Locations

Specialties & Treatments

Treatment & Services

  • Adolescent Endocrinology
  • Cardiovascular Disease Risk Prevention
  • Diabetes Center
  • General Endocrinology
  • Male Infertility Testing
  • Medical Weight Management
  • Radioactive Iodine Treatment
  • Thyroid Aspiration
  • Thyroid Ultrasound
  • Thyroid Ultrasound and Biopsy
View all 10 Treatment & Services +

Specialty in Diseases & Conditions

  • Acromegaly
  • Addison's Disease
  • Adrenal Disorders
  • Adrenal Insufficiency
  • Adrenal Tumors
  • Adrenocortical Carcinoma
  • Adrenoleukodystrophy (ALD)
  • Alopecia Areata
  • Amenorrhea
  • Androgen Deficiency (Low Testosterone)
  • Androgen Excess
  • Beta-Cell Disorders
  • Bone Disorders
  • Calcium Disorders
  • Carcinoid Syndrome
  • Conn's Syndrome
  • Cushing's Syndrome
  • Diabetes
  • Diabetes, Gestational
  • Erectile Dysfunction
  • Familial Multiple Endocrine Neoplasia
  • Fasting Hypoglycemia
  • Flushing Syndromes
  • Galactorrhea
  • Goiter
  • Growth Hormone Deficiency
  • Growth Hormone Excess
  • Gynecomastia
  • Hair Loss
  • Hair Loss in Women
  • High Blood Pressure (Hypertension)
  • High Cholesterol
  • Hirsutism
  • Hyperaldosteronism
  • Hyperandrogenism
  • Hypercalcemia
  • Hyperprolactinemia
  • Hyperthyroidism
  • Hypertriglyceridemia
  • Hypocalcemia
  • Hypogonadism
  • Hypoparathyroidism
  • Hypophysitis
  • Hypopituitarism
  • Hypothyroidism
  • Ketogenic Diet
  • Klinefelter Syndrome
  • Male Infertility
  • Menopause, Male
  • Metabolic Diseases
  • Metabolic Syndrome
  • Neuropathy - Diabetic
  • Obesity
  • Osteopenia
  • Osteoporosis
  • Panhypopituitarism
  • Parathyroid Disease
  • Pheochromocytoma
  • Pituitary Disorders
  • Pituitary Tumors
  • Polycystic Ovary Syndrome
  • Primary Hyperaldosteronism
  • Prolactin Excess States
  • Prolactinoma
  • Pseudohypoparathyroidism
  • Reactive Hypoglycemia
  • Secondary Hyperparathyroidism
  • Sexual Dysfunction
  • Sexual Hormone Disorders
  • Tertiary Hyperparathyroidism
  • Thyroid and Pregnancy
  • Thyroid Cancer
  • Thyroid Disease
  • Thyroid Nodule
  • Vitamin D Deficiency
View all 75 Specialties +


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Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - Mayo Clinic
Rochester, MN

Residency - Duke University Medical Center
Internal Medicine
Durham, NC

Internship - Duke University Medical Center
Internal Medicine
Durham, NC

Medical Education - Johns Hopkins University School of Medicine
Baltimore, MD

Undergraduate - University of Michigan
Ann Arbor, MI


  • Internal Medicine
  • Internal Medicine - Endocrinology, Diabetes and Metabolism

Specialty Interests

Type I and Type II diabetes, adult growth hormone deficiency, hypothyroidism, hyperthyroidism, thyroid nodule, hypogonadism, pituitary adenoma, adrenal insufficiency, hypercalcemia

Research & Publications

Research & Publications

See publications for Robert Zimmerman, MD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 3/28/2024, Dr. Zimmerman has reported the financial relationships with the companies listed below. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

218 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.8 out of 5
Explains 4.8
Courtesy, Respect & Concern 4.8
Patient Rating of Doctor 4.7

36 Patient Comments

Reviewed on May 24, 2024

Dr Zimmerman is very thorough

Reviewed on May 24, 2024

Every single time Dr. Zimmerman is late, and not just a little bit late. This time it was 45 minutes. I'm not sure why health care providers expect patients to not only be on time, but early, then they don't reciprocate the same. Obviously things happen, but if roles were reversed the patient would be forced to forfeit and reschedule.

Reviewed on May 17, 2024

Actually Dr. Robert S. Zimmerman on a scale of 1 to 5, with 5 being the best score, is rated a 7. He is a great doctor in all respects!

Reviewed on May 17, 2024

I have nothing but praise for Dr. Zimmerman!

Reviewed on May 10, 2024

Video visit requests you arrive 15 minutes early - provider was 30 minutes late -

Reviewed on May 6, 2024

Dr Zimmerman has so much experience and knowledge and he always takes time to listen and explain everything. He is the best!

Reviewed on May 6, 2024

Dr Zimmerman spent a significant amount of time with me , providing information, asking questions, reviewed medical records, and provided appropriate medication. Dr Zimmerman was also an excellent teacher , helping my wife and me understand how to control my high glucose.

Reviewed on Apr 29, 2024

The MD was excellent.

Reviewed on Apr 19, 2024

My visits with Dr. Zimmerman are always professional and extremely helpful . He is a very kind human being as well as great Doctor.

Reviewed on Apr 16, 2024

I always receive excellent service from Dr. Zimmerman

Reviewed on Apr 16, 2024

Visit worked well I could not get into zoom but was able to reach out to Dr Zimmerman and we did a FaceTime it worked fine Dr Zimmerman was very helpful in getting our visit able to be completed

Reviewed on Mar 21, 2024

Dr. Zimmerman is an excellent doctor. He is very knowledgeable and care about his patients. I feel safe and confident with his care.

Reviewed on Mar 21, 2024

Dr.Zimmerman always kind, attentive, informative

Reviewed on Mar 19, 2024

Dr Zimmerman listens to me and addresses my concerns, I really appreciate working with him.

Reviewed on Feb 9, 2024

I have found that the video visit has worked very well for me. I have been a patient of Dr. Zimmerman for years and I am sure that his familiarity with me and my particular symptoms contributes strongly to the effectiveness of the video visit.

Reviewed on Dec 18, 2023

Doctor is great but it seems he is buzy a lot

Reviewed on Dec 7, 2023

Dr. Zimmerman is wonderful and always ready to answer questions.

Reviewed on Dec 5, 2023

Dr. Zimmerman Is and for years has been an outstanding, caring, communicative physician. He exemplifies the CCF culture that stresses a positive patient experience. He is the poster Doc for that god experience.

Reviewed on Dec 1, 2023

I have been very pleased with the remote visits with Dr. Z.

Reviewed on Dec 1, 2023

Dr Z is very thorough. I am completely satisfied with my care under his authority. I have kept my a1 c under 6.5 and have loss nearly 70 lbs with very few regain instances. And I rarely feel ill m

Reviewed on Nov 29, 2023

This is my first visit to Dr. Zimmerman. He has enormous knowledge, was thorough, clear, and firm about his plan of my treatment. I took his instructions and look forward to seeing him in three months.

Reviewed on Nov 22, 2023

He's obviously a qualified physician but not the most personable person on the planet. Every time I come in, he doesn't seem to know who I am whereas my other physicians at CC have taken good notes and know exactly who I am and what issues we discussed the last time before they even come into the room.

Reviewed on Nov 7, 2023

I have been Dr. Zimmerman's patient for about 15 years. He is exceptionally competent in his areas of expertise. His "bedside" manners are outstanding! In some ways, I'm still alive and healthy, thanks to him!

Reviewed on Oct 30, 2023

When the doctor request a apointment for 3month, his schedule is already full

Reviewed on Oct 27, 2023

Dr Zimmerman is very understanding

Reviewed on Oct 27, 2023

DR Zimmerman Always remember who I am.. And that means a lot to me because I know you have a lot of patients

Reviewed on Oct 27, 2023

Dr. Zimmerman is unquestionably knowledgeable, direct, answers questions, and, most importantly, listens. As my physician father in-law was wont to say -- a doctor's ears are her most important diagnostic tool.

Reviewed on Oct 11, 2023

Dr Zimmerman is the best specialist I have ever seen. I have been his patient for more than 7 years and he always listens, helps and encourages me . He is very knowledgeable and also very kind.

Reviewed on Oct 5, 2023

Doc Z was really on his game.

Reviewed on Sep 22, 2023


Reviewed on Sep 20, 2023

Dr. Zimmerman has always been kind and treated me with respect.

Reviewed on Sep 11, 2023

This is my 3rd time to see Dr. Zimmerman. I was with my last Endrocrinologist 45 years. I really like Dr. Zimmerman.

Reviewed on Sep 11, 2023

I have already recommended Dr. Zimmerman or practice.

Reviewed on Aug 28, 2023

Dr. Zimmerman listened carefully and carefully answered my questions.

Reviewed on Aug 11, 2023

Dr Zimmerman is a wonderful physician who is very easy to talk to, understanding and compassionate. I have recommended him to quite a few of my friends and colleagues!

Reviewed on Jul 14, 2023

Dr.Zimmerman is wonderful !

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