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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
  • Diabetes Center
  • General Endocrinology
  • Medical Weight Management
  • Radioactive Iodine Treatment
  • Thyroid Aspiration
  • Thyroid Ultrasound
  • Thyroid Ultrasound And Biopsy
View all 8 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
  • Cardiovascular Risk Prevention
  • 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 Cholesterol
  • Hirsutism
  • Hyperaldosteronism
  • Hyperandrogenism
  • Hypercalcemia
  • Hyperprolactinemia
  • Hypertension - High Blood Pressure
  • Hyperthyroidism
  • Hypertriglyceridemia
  • Hypocalcemia
  • Hypogonadism
  • Hypoparathyroidism
  • Hypophysitis
  • Hypopituitarism
  • Hypothyroidism
  • Ketogenic Diet
  • Klinefelter Syndrome
  • Male Infertility Testing
  • Menopause, Male
  • Metabolic Diseases
  • Metabolic Syndrome
  • Neuropathy - Diabetic
  • Obesity
  • Osteopenia
  • Osteoporosis
  • Panhypopituitarism
  • Parathyroid Disease Description
  • 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 76 Specialties +


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Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - Mayo Clinic
Rochester, MN USA

Residency - Duke University Medical Center
Internal Medicine
Durham, NC USA

Internship - Duke University Medical Center
Internal Medicine
Durham, NC USA

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

Undergraduate - University of Michigan
Ann Arbor, MI USA


  • 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 11/6/2020, Dr. Zimmerman has reported no financial relationship with industry that is applicable to this listing. 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

175 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 4.8

39 Patient Comments

Reviewed on May 17, 2021

Dr. Zimmerman and staff are amazing.

Reviewed on May 11, 2021

The video conference worked as well, if not better, than an in person visit. Dr. Zimmerman was on time and the video conference was as inclusive as an in person visit. All too often an in person visit is delayed and does not start on the scheduled time. I have found the video appointments to more likely adhere to the schedule.

Reviewed on Apr 22, 2021

he has thought me a lot about stuff I've never heard of made me more aware of my body and what food to eat to take care of me He's patient and forthcoming will let me know if you're doing anything wrong with your health I'd definitely appreciate him as my doctor as a person and as a healthcare provider He don't know it but he definitely save my life and I really appreciate him

Reviewed on Apr 6, 2021

Doctor Zimmerman was very conscientious about reviewing information/reports/test results from appointments with previous providers as a follow up. This was my first appointment with Dr Zimmerman and I appreciated his willingness to listen to my concerns and help to determine best next step for my situation.

Reviewed on Mar 30, 2021

Dr. Zimmerman is simply superb. He is extremely focused and caring for me as a long term patient no longer near Cleveland for current visits. He remembers all pertinent information about me, both medical and personal. Although he is an endocrinologist I still consider him to be my primary physician.

Reviewed on Mar 30, 2021

Dr. Zimmerman is simply tops.

Reviewed on Mar 29, 2021

He very personable, polite, and a great Dr.

Reviewed on Mar 29, 2021

For the years I have gone to Dr. Zimmerman I always tell people about him

Reviewed on Feb 19, 2021

Dr. Zimmerman is always very professional and concerned about my health.

Reviewed on Jan 25, 2021

i unfortunately demanded to see another provider which was a mistake. the provider i originally scheduled with was certified in 3 areas related to my current problem that i was seeking advice in. the provider i saw, dr. zimmerman, specializes in a different condition. i felt bad in the end that i likely wasted his time and put him behind in his schedule as i was added on.... i have no complaints about his care, he was kind and addressed my questions. but i did not get the fluent level of expertise and breadth of knowledge that i would have from the specialist. i did not learn much than i already knew with my own research and networking....

Reviewed on Jan 11, 2021

dr Zimmerman is the best dr we have encountered during the last ten years dealing with complex chronic illnesses. his treatment plans are always updated and show results. Dr Zimmerman listens and cares for the whole patient . he is extremely knowledgeable and always takes his time to explain lab results , treatments , etc. we can not thank him and recommend him highly enough

Reviewed on Jan 5, 2021

Dr. Zimmerman is a wonderful caring doctor!

Reviewed on Jan 4, 2021

Excellent and friendly doctor

Reviewed on Dec 18, 2020

dr. Zimmerman is a great guy.

Reviewed on Dec 14, 2020

I am always completely satisfied when ever I have an appointment with Dr. Zimmerman.

Reviewed on Dec 14, 2020

Never ever have I had a bad experience when I have any appointment with Dr. Zimmerman and the entire staff.

Reviewed on Dec 1, 2020

I completely appreciate and value Dr. Zimmerman as a person and a professional. His influence motivates me daily to care for my diabetes and I fare well because of him. take good care of him.

Reviewed on Nov 20, 2020

Dr Zimmerman was curious and looking for a solution to my problem

Reviewed on Nov 13, 2020

dr. Zimmerman is amazing

Reviewed on Nov 13, 2020

Dr Zimmerman always listens . Highly recommend

Reviewed on Nov 12, 2020

In addition to his exceptional expertise in endocrinology, Dr Zimmerman is the most caring doctor I have ever worked with. He asks me questions and takes time to really listen and discuss problems and to explain treatments. I am very fortunate to be his patient. Thank you

Reviewed on Oct 23, 2020

Dr. Zimmerman is always concerned about the health of his patients.

Reviewed on Oct 6, 2020

He's a great doctor but I've been trying to solve a very complex issue and I don't know how to go about or even explain it correctly so I'm a problem but he's GREAT and everyone at the Cleveland Clinic is fantastic. That's why I tried because you are the best and I've seen hundreds of doctors here in PA with no satisfactory results and I'm just chasing my tail and I'll just continue on my path. I can confuse doctors by my home easier. I don't know what to do with my terrible feeling. It's has to be me. Maybe this is the best I'll be

Reviewed on Oct 5, 2020

dr Zimmerman is excellent

Reviewed on Sep 14, 2020

Dr Zimmerman is always attentive great listener great advice.

Reviewed on Sep 4, 2020

great doctor

Reviewed on Aug 31, 2020

Dr. Zimmerman could have not been more caring and knowledgeable. He was a very good listener and was able to frame the exact question I sometime was trying to explain. Truthfully, I have not had this kind of patient doctor interaction in a long time and it was so very helpful. I have and will recommend Dr. Zimmerman

Reviewed on Aug 31, 2020

Dr. Zimmerman is the best Endo dr. that I've had in 40 yrs. very polite, understanding, and intelligent! thank you Dr.

Reviewed on Aug 31, 2020

Dr.Zimmerman was amazing!

Reviewed on Aug 4, 2020

Our discussion exposed an opportunity for Dr. Z's staff to help patients prepare and make available required blood glucose data and charts from CGM devices before the appointment date/time. This would aid Dr. Z's staff and the patient in managing patient health.

Reviewed on Jul 29, 2020

I have always been impressed with the efficiency and care of Dr.Zimmerman and his staff.

Reviewed on Jul 21, 2020

I was very impressed with Dr Zimmerman. He took time and really listened to me.

Reviewed on Jul 17, 2020

dr Zimmerman listens carefully and very courteous. Explains treatment and lab results clearly.

Reviewed on Jul 14, 2020

This was our first visit and the Dr. was amazing with explaining, and being considerate of Marisa's feelings and having anxiety, and autism.

Reviewed on Jul 10, 2020

Dr zimmerman is awesome

Reviewed on Jun 25, 2020

my appointment with Dr. Zimmerman was very good he was very informing and acknowledging of my goals to lose weightHe did refer me to a dietitian

Reviewed on Jun 25, 2020

Dr. Zimmerman was very willing to discuss issues of my occasional very low and high sugar readings.

Reviewed on Jun 9, 2020

Dr. Zimmerman is always aware of my history and treats me both with professionalism and with concern.

Reviewed on Jun 1, 2020

Good. Dr. Z was very personable and attentive

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