Diana L. Maas, MD

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4.9 (170)
Associate Professor
Accepting New Patients
Offers Virtual Visits

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New & Established Patients Call 414-805-3666
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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


Endocrinology - Froedtert Hospital
8750 William Coffey Dr.
Milwaukee, WI 53226
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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

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.

4.9 out of 5. 170 ratings, 41 reviews
Oct. 24, 2020
I really like Dr. Maas and the team and feel fortunate to have them on my team. thanks!
Oct. 14, 2020
love dr. mass and her staff. have never had issues
Oct. 7, 2020
Always a excellent experience.
Oct. 7, 2020
Dr Maas and all the staff are very nice to work with.
Oct. 7, 2020
Always very through and follows up with prior years concerns.
Oct. 7, 2020
Dr Maas true professional. she was precise and understandable in her review of my ultrasound in comparison to previous ultrasounds.
Sept. 22, 2020
She covered everything and made sure I understood everything
Sept. 17, 2020
Dr Maas it the most caring, understand, helpful Dr. I actually look forward to seeing her because she feels like a family member and we can talk about anything.
Sept. 10, 2020
I enjoyed how Dr. Maas & her staff worked together.
Sept. 6, 2020
Dr. Maas is an excellent Physician who I would recommend to anyone who is afflicted with a Petuitary issue. She is kind and truthful and understanding of a Patients needs. She began treating me in 2017 and for the surgery I had to remove a Tumor on my Petuitary gland.
Sept. 3, 2020
Dr Maas has an amazing beside manner. she is so kind and really shows she cares. it's my favorite annual doctor appointment I have.
Sept. 2, 2020
I am not just a patient by record. my doctor actually KNOWS ME. that means the world to me
Aug. 27, 2020
Dr. Maas is so easy to talk to - she always answers my questions completely. She appears extremely knowledgeable and I feel very confident having her for my endocrinologist.
Aug. 25, 2020
Listened, didn't dismiss concerns, used empathy, made sure I felt comfortable
Aug. 14, 2020
The provider reviewed my health history and the health history of my family to understand the context of my current general health... very thorough!
Aug. 13, 2020
Dr. Maas is the very best!
Aug. 10, 2020
Dr. Maas is an excellent physician. We have a very comfortable patient/doctor relationship. There is always sufficent follow up if I have any issues between my visits with Dr. Maas. Her staff is excellent.
Aug. 6, 2020
Dr Maas is very smart, very pleasant, and knowledgeable in her field. She is a beautiful woman inside and out.
July 23, 2020
Dr. Maas is wonderful! She knows me and supports me with anything I need!
July 15, 2020
Dr. Maas was so caring , so thorough she explained everything really well and she listened carefully to my concerns
July 2, 2020
She listens to me about symptoms, runs test, and adjust medication based on both of those, not just test results.
June 23, 2020
Dr. Maas is an excellent physician! She always listens to me and my concerns and offers great advice and support.
June 21, 2020
My wife and I love Froedtert it's saved my life the doctors there, and as far as Dr. Maas goes we love her she is an excellent physician
May 4, 2020
they make you feel like the only patient in the office
May 1, 2020
This was the first time I did a "virtual visit" I thought it was EXCELLENT. Dr Maas is very thorough, enthusiastic about results and supportive at all times. I have worked as an RN for 42 yrs and she is one of my top 3 providers!!
April 29, 2020
The best and very honest care provider I've ever met. I feel blessed to have this best care provider. God bless America
Feb. 22, 2020
couldn't find a better doctor/team
Feb. 19, 2020
Dr. Maas and her staff are always outstanding. I have been seeing her for many years and she is always wonderful.
Feb. 17, 2020
dr maas listened to me
Feb. 15, 2020
Everyone (in the Endocrine Clinic) is exceptionally caring! I feel respected and heard! Kudos!
Feb. 12, 2020
I have not felt well for the last 4 times I've seen her, I've told her the medication change is not enough. I'm always leaving feeling like I wasn't listened to and my opinions on how I wish to to be treated are not listened to. I will be shopping for a new doctor.
Feb. 11, 2020
Dr. Maas has been an exceptional care provider. She is always engaged, informative and very attentive. I trust her judgment and would highly recommend her services.
Jan. 20, 2020
Dr. Maas is extremely thorough and shows genuine care for me and my health
Jan. 18, 2020
Dr. Maas is the most knowledgeable endocrinologist in my experience as a patient. It was evident that she has a passion for her profession. She takes great care of her patients. Her staff was very caring also.
Jan. 14, 2020
extremely professional and courteous
Jan. 9, 2020
overall experience of provider being an expert in the field and great communicator
Jan. 3, 2020
Dr Maas is caring, listens and takes an overall interest in my well being. She is a wonderful physician and I am so fortunate to be her patient.
Dec. 22, 2019
Everyone was so happy and helpful
Dec. 22, 2019
Everyone on the staff was pleasant, helpful, professional and took the time to answer questions I asked and they were very knowledgeable about my health history
Dec. 20, 2019
I've been seeing Dr. Maas for many years, where I started seeing her because of a cyst that was found on my pituitary gland. And then due to under active thyroid where she started me on medication. I was seeing a MD where she did lab work and said due to the results she needed to change the dosage/strength of my Levothyroxine. I tried to explain that Dr. Maas has said that "my normal" is everyone else's abnormal and vise versa. Needless to say I'm no longer seeing that MD any longer. I will travel wherever to see the Best and I feel Dr Maas is the Best!! Most of the time she is also out of network for me as well!!!!!!!
Dec. 18, 2019
very knowledgable & expert in her field, very caring & compassionate, excellent listener & explainer, she really knows me & understands my medical history, outstanding follow-up
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