Diana L. Maas, MD

Associate Professor
Accepting New Patients

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New & Established Patients Call 414-777-7700
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My philosophy of care is to take the time to educate patients about their medical condition so that they can share in the decision making processes of their care.

My philosophy of care is to take the time to educate patients about their medical condition so that they can share in the decision making processes of their care.


Dr. Maas has been involved in the specialty of Endocrinology, Diabetes and Metabolism since early 1990. She received her medical training and completed her residency and fellowship at the Medical College of Wisconsin and Affiliated Hospitals. Dr. Maas is an Associate Professor of Medicine and the Director of the Pituitary Clinic. She works with the neurosurgeons as a team to take care of patients with pituitary tumors.


Treatment & Services

Virtual Visit

Diseases & Conditions

Adrenal Disorders
Cushing's Syndrome
Parathyroid Disease
Pituitary Disorders
Thyroid Disease

Ages Seen


Languages Spoken


Hospital Affiliations

Froedtert Hospital


8850 William Coffey Dr.
Milwaukee, WI 53226
Endocrinology - Froedtert Hospital

Education & Training

Medical College of Wisconsin - Milwaukee - Doctor of Medicine - (1985)

Medical College of Wisconsin - Milwaukee - Residency in General Internal Medicine - (1985-1988)

Medical College of Wisconsin - Milwaukee - Fellowship in Endocrinology & Metabolism - (1988-1991)

Board Certifications

Endocrinology, Diabetes and Metabolism
Internal Medicine

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Please check with your insurance to verify coverage. If scheduling for a COVID-related reason, procedure or injection, or for additional appointment options, call 414-955-6660.

Have you seen this doctor or clinician within the last 3 years?

Patient Reviews

The comments are submitted by patients (or their caregivers) and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of the Froedtert & the Medical College of Wisconsin health network. Learn more about our survey.*


* Due to high volume, only the most recent 30 comments are displayed for a selected value.

Dr Maas is incredible. Compassion, knowledge and validation are not often found in the land of endocrinology.
Dr Maas is a wonderful physician and when she retires in October she will certainly be missed.
Dr Maas talked to me on the phone for audio. The video part worked well
Dr. Maas is absolutely "The best"!
Dr. Maas has provided outstanding care for me over the decades. Knows her patient and has taken time to get to know me as a patient.
Best care I have ever received in my 44 years alive, period. Amazing people.
Very professional and helpful.
Dr. Maas is among the top providers I have ever had. She takes the time with her patients as if she only sees one per day! She is above all professional, experienced and in my case, works with other specialists in the field to provide the best treatment plans and options.
Dr. Maas is my angel. She has been taking care of me for the last 22 years. I just can't thank her enough for giving me the best care in the world.
Dr. Maas is the best! She is caring and conscientious - everything I could ask for in a provider.
Dr Maas is totally awesome. She is a shining star among her peers!! I would love to see her stay part time!!
Dr. Maas did an excellent job of reviewing past exam & outcomes. She shared her clinical expertise in our discussions. As a health care clinician I would give her the highest rating and let her know how much I appreciate her care & attention.
Dr. Maas is an excellent doctor. She is kind, caring, respectful, thorough and professional.
Dr Maas is an excellent physician and an asset to the Froedtert endocrinology clinic.
Just never got my next appointment info in writing when I left- somehow that got missed and it was end of day so no one was at the checkout desk. I love this provider!! Dr. Maas is excellent. Her staff is excellent. Top notch Dr!!
Usual good quality of treatment
When I have an appointment with Dr. Maas, she is always so pleasant, answering all my questions and is extremely caring. I always go away from her visit with a happy feeling. She is a tremendous physician and has helped me very much with my health problems.
Dr Maas is always thorough and compassionate
Dr. Maas is excellent. I have a long term relationship with her. She understands what I want from medicine, and is just very good. A treasure really! So glad to have her on my team.
Dr. Maas being an out of network care doctor has done absolutely everything she could do to get the care I need but also be mindful of the cost that would incur. She is an exceptional doctor!!! She has fit me in both times I have seen her on last notice due to flares and needing treatment right away. I appreciate her very much!
Dr. Maas gets an A+ rating. She is highly professional and knowledgeable, very personable, and extremely caring. Feeling blessed that I have her on my medical team.
Dr. Maas is professional, personable and friendly. I would strongly recommend Dr. Maas to everyone.
The doctor was very pleasant and very concerned about my health.
Excellent care provided by my doctor
Dr Maas is an incredible provider. My health has improved significantly under her care. He assistant today was just exceptionally- bery caring and concerned.
Dr. Maas is so awesome. Her bedside manner is amazing.
Very friendly and efficient experience.
Dr. Maas always listens. I feel heard, understood and appreciated.
A very informative visit
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