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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 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 - Endocrinology, Diabetes and Metabolism
  • Internal Medicine

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 11/1/2023, 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

215 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

41 Patient Comments

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 !

Reviewed on Jul 3, 2023

I would highly recommend to other patients like myself

Reviewed on Jun 28, 2023

Dr Zimmerman is extremely knowledgeable and very empathetic. He is the best specialist we have ever been to and are fortunate to be in his care for over 7 years.

Reviewed on Jun 19, 2023

Dr. Zimmerman spent so much time listening to my concerns and working to find a solution. I honestly don't think I've ever felt more heard' by a physician.

Reviewed on Jun 19, 2023

I would fully recommend Dr. Zimmerman to anyone needing to see an endocrinologist.

Reviewed on Jun 14, 2023

Dr Zimmernann takes time to listen to the concerns of the patients and to explain questions related to my issues!!

Reviewed on May 23, 2023

Dr. Zimmerman has always gone out of his way to help me.

Reviewed on May 19, 2023

He is a very thorough doctor. I was not pleased with my diabetes care until I started with dr z.

Reviewed on May 12, 2023

Excellent Doctor very precise and knowledgeable

Reviewed on May 12, 2023

I would recommend this Doctor He is very knowledgeable and a great Doctor

Reviewed on Apr 28, 2023

Dr. Zimmerman was very professional and polite.

Reviewed on Apr 24, 2023

Excellent experience. It was my first visit with Dr. Zimmerman and I'm very comfortable knowing I'm going to get the best care possible.

Reviewed on Apr 21, 2023

Excellent Dr. Extremely knowledgeable and up to date.

Reviewed on Apr 14, 2023

Dr. Zimmerman is excellent Doctor in everything! He is very kind, answers all questions, always respectful !

Reviewed on Apr 10, 2023

Dr Zimmerman has provided excellent care in treating my diabetes . I feel so comfortable with him. The clinic staff has been wonderful to work with. Keep up the good service.

Reviewed on Mar 17, 2023

He is excellent Doctor in everything

Reviewed on Mar 13, 2023

Dr. Zimmerman is very kind, listens, answers questions, does not rush me in and out, always respectful.

Reviewed on Mar 3, 2023

Love Dr Z! He listens and answers all questions!

Reviewed on Mar 3, 2023

Love Dr Z!

Reviewed on Mar 2, 2023

Very good experience. I am grateful to have Dr. Zimmerman on my healthcare team. He took time to patiently answer my questions and allowed me to participate in shared decision making

Reviewed on Feb 16, 2023

Great Doctors and great Staff .

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