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.



Diseases & Conditions

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

Treatment & Services

Virtual Visit

Ages Seen


Languages Spoken


Hospital Affiliations

Froedtert Hospital


8750 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

Schedule Online Now

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

Have you seen this provider 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 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
Exceptional treatment, respect, and care by both the nurse, and Dr. Maas.
Dr. Maas is simply the best! Besides being caring and professional, she diagnosed a condition that two other doctors missed. Froedtert is lucky to have her.
My experience was very favorable. Dr. Maas is always a pleasure, as she is very thorough and clear to understand.I would recommend Dr. Maas to anyone with an issue of a Petuitory issue.Dr. Maas prepared me for the surgery that I had in 2017.
Have been a patient of Dr Maas for over 21 years. Have always liked her care and those of her assistance/nurses.
Friendly professional and enjoyed our visit
Dr. Diana Maas and staff are great!
Dr Maas is an excellent doctor and had helped me very much. She is very easy to talk with and listens to what I have to say. I look forward to seeing her because I know she will help me and she always steers me in the right direction and gives good advice. I have never had a bad experience with any staff in this specialty clinic
Thank you for all the attention and hard work.
Dr. Diana Maas is the best doctor I have ever had. She is caring, supportive, and listens to you. She is the best.
Dr. Maas is an excellent physician!
Dr. Maas is always very professional while also being patient friendly. She gives 100% of her attention, never making me feel rushed.
Greatly appreciate the Kindness, Care and Expertise Dr. Maas and the Endocrine Group provide with each visit.
Dr Maas is outstanding in every way! She is the best!!!!'n
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