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 5/21/2019, 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.

Consulting and/or Speaking. Dr. Zimmerman receives fees of $5,000 or more per year as a paid consultant, speaker or member of an advisory committee for the following companies:

  • Merck & Co., Inc.

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

155 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
4.7 out of 5
Explains 4.7
Listens 4.7
Courtesy, Respect & Concern 4.8
Knows Medical History 4.6
Time Spent with Patient 4.8
Patient Rating of Doctor 4.7

28 Patient Comments

Reviewed on Aug 8, 2019

Doctor was very good in answering all my questions, gave suggestion which were helpful. Completely satisfied with Dr. Zimmerman.

Reviewed on Aug 2, 2019

Dr. Zimmerman was kind and thorough and patient. Great experience!

Reviewed on Jul 29, 2019

very pleased with Dr and pharmacist and nurses

Reviewed on Jul 24, 2019

I feel healthier than I had in the past and Dr. Zimmerman listens to my concerns and works diligently to address them.

Reviewed on Jul 24, 2019

I drive 65 miles each way to see this doctor after having little success with my primary care physician in dealing with my illness.

Reviewed on Jul 23, 2019

Dr Zimmerman has always been an excellent caregiver.

Reviewed on Jul 15, 2019

we have to drive there from New York and Dr Zimmerman is always so kind to work on times in his schedule when we can get an appointment with him when we work directly with him. He has even come in early or stayed late for us before. we appreciate his time very much.

Reviewed on Jul 15, 2019

Dr Zimmerman is one of the best physicians I have ever met. He is not only so knowledgeable and experienced but he also shows the utmost respect and care and concern for me as a patient. I would recommend him most highly and really cannot thank him enough for his time and attention to my health concerns over the years.

Reviewed on Jun 26, 2019

He is a excellent Doctor

Reviewed on Jun 21, 2019

The entire time he's talking to his resident NOT ME! Talked all around me the entire visit. I sat in the room for over 40 minutes I had to leave out just to remind the doctor of my appointment time.

Reviewed on Jun 19, 2019

Dr. Zimmer and Staff are excellent, at their jobs. Dr. Is thorough and detail oriented. Good Job!

Reviewed on Jun 19, 2019

I receive excellent care from Dr. Zimmerman & staff

Reviewed on Jun 18, 2019

I definitely look forward to my health visit I'll be excited when Dr. them or say that I'm doing great he definitely motivates me, in that being a doctor is a great thing

Reviewed on May 9, 2019


Reviewed on May 6, 2019

I have has Dr. Zimmerman as my Endocrinologist for years. He is a dedicated physician and knowledgeable in his field of expertise.

Reviewed on Apr 11, 2019

This was my first appointment with Dr. Zimmerman and I not only was scheduled for the appointment in a very short time, the staff in his office were all very pleasant, and friendly. I was impressed with Dr. Zimmerman as I felt he LISTENED to me and did not make me feel like I was some old lady in his office babbling about my health. The outcome of my appointment was a major change in my medications and I was blown away in receiving two phone calls from Dr. Zimmerman personally and his salutation to take care of my self and have a good weekend were very much appreciated. This was a first from a physician from CCF and all of my Providers are through the CCF, other than my surgeon who did make phone calls often to check up on my previous surgeries and how I was doing. I am very impressed with Dr. Zimmerman and am glad my search and decision on Endocrinologists led me to Dr. Zimmerman.

Reviewed on Apr 8, 2019

Dr Z is REASONABLE and I would definitely recommend him to others

Reviewed on Mar 18, 2019

My Husband just love DR. Zimmerman and his staff!! :) They are always always pleasant!

Reviewed on Feb 26, 2019

Dr. Zimmerman always takes time to review my most recent blood work results, compare with previous results, and make suggestions.

Reviewed on Feb 20, 2019

doctor is excellent and very helpful

Reviewed on Feb 13, 2019

Excellent Doctor. cares about patients. Great listener. Went over and above to work with me on several issues.

Reviewed on Dec 13, 2018

dr asked lots of wuestions but is a poor listener. He is excellent at obective parameters in looking at my health but a physician who seems to ask the wuestions because he is supposed to. there was no follow up including when he asked about depression, mood. Not sure I will continue seeing him.

Reviewed on Dec 3, 2018

When I was there I had to wait a while. Even Dr. Zimmerman walked out and waived as he didn't have any other patients and was just waiting on me. For some reason even though he wasn't busy I still had to wait in the lobby for I think a good 15 to 20 minutes, neither of us understood why.

Reviewed on Oct 25, 2018

he did not talk much. Incomplet esnetences and I really never got any clear structured information from him. I am eduacted and i trained physician myslef so i thanfully didi not need him eto explain anything. But he should have talked to me. He sat there talking to himself.

Reviewed on Oct 9, 2018

doctor called with results and personally instructed the following procedures

Reviewed on Oct 2, 2018

My experience was excellent. Dr. Zimmerman is a most caring physician and treated me with respect and gave me the confidence I needed concerning my diagnosis.

Reviewed on Sep 18, 2018

Only problem is they didnt have records that we mailed a month before. Webrought copies and Dr Zimmerman read and used them often.

Reviewed on Sep 18, 2018

We left so excited that Dr Zimmerman understood problem and acted sincere about helping.

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