COVID-19 (Coronavirus) Update: Testing and Information | Vaccine Updates | Visitor Guidelines

Diana L. Maas, MD

Associate Professor
Accepting New Patients

Call for an appointment

New & Established Patients Call 414-805-3666
Call for an appointment
Accepting New Patients
Call for an appointment
New & Established Patients Call 414-805-3666

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

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. 227 ratings, 51 reviews
April 19, 2022
Greatly appreciate the Kindness, Care and Expertise Dr. Maas and the Endocrine Group provide with each visit.
April 9, 2022
Dr Maas is outstanding in every way! She is the best!!!!'n
March 10, 2022
In addition to providing the care for which I came to her, Dr. Maas went well beyond that care, trying to assist me with recent issue unrelated to endocrinology, and did, to the best of her ability provide me with critical information that should have been provided to me through another practitioner at an entirely different clinic. Seeing Dr. Maas is always helpful, but this visit was particularly so.
March 10, 2022
Dr. Maas is the best!
March 3, 2022
Dr Maas is always very caring and easy to talk with.
March 2, 2022
I learned more about my visit reading the doctor notes after than during my examination
Feb. 24, 2022
Dr. Maas is the one of the best doctors!
Feb. 21, 2022
Always a pleasure to see Dr. Maas.
Feb. 5, 2022
Dr. Maas is an outstanding doctor!
Jan. 29, 2022
Dr. Maas is an excellent physician. She goes above and beyond for her patients.
Jan. 28, 2022
Dr Maas is fantastic! It is always a pleasure seeing her. She is the best!!!!
Jan. 26, 2022
Dr. Mass always in kind gentle and knowledgeable in her care. She is the reason I'm at Froedtert PERIOD
Jan. 26, 2022
Dr. Maas is one of the best healthcare providers I have, and I always enjoy my appointments with her and come away well informed. I have recommended her to others with endocrine issues.
Jan. 7, 2022
Dr. Maas has always been on top of my conditions and honestly takes the most thorough, specific, & helpful After-Visit Notes available on MyChart in comparison to my other doctors/departments I see (which includes neurology & neuro-ophthalmology) I trust & value her opinion and eye for detail, and hope to continue my care with her for years to come.
Dec. 23, 2021
I feel very fortunate to work with Dr Maas. She is compassionate, very skilled, caring, and explains thing clearly. She really listens to me and answers my questions.
Dec. 23, 2021
Dr. Maas is the best Dr. She is friendly, smart, and very understanding. I live in Florida but come to Froedtert because I believe she is the best person to take care of me.
Dec. 20, 2021
Dr. Maas is the best.
Dec. 18, 2021
My provider, Dr. Mass, is simply outstanding. She is through, involved and listens in depth to my concerns and issues.
Dec. 14, 2021
I love the care Dr Diana Maas provided for me. She is a very kind, caring and compassionate physician and I would highly recommend her to others.
Dec. 9, 2021
Dr. Maas has been my doctor for a long time. She has always taken the time to listen to me and answer my questions.
Dec. 7, 2021
Great doctor. Helped much.
Dec. 6, 2021
Love Dr. Maas! She is compassionate, informative, helpful and efficient! Her fellow was also great!
Dec. 3, 2021
All went well.
Nov. 23, 2021
I love Dr Maas who shows a genuine concern about my health current and future. I rated all categories very good because I am completely satisfied with my experience with the endocrine dept, but especially Dr Maas.
Nov. 18, 2021
She is an excellant provider.
Nov. 18, 2021
Dr. Maas is the best!!!
Nov. 3, 2021
No, always have great visits with Dr. Maas.
Nov. 2, 2021
Provider is excellent. New location is difficult to access
Oct. 7, 2021
Dr Maas is incredible! I am consistently impressed with the care I receive from Dr Mass. She is the best physician I've ever met.
Oct. 5, 2021
Dr. Maas is amazing. She really listens and Is so sweet. Her knowledge In her field Iis outstanding. She's the best !
Sept. 30, 2021
Dr. Mass is always a pleasure to visit! Can't say enough about her and her care.
Sept. 26, 2021
Dr. Maas is a, extremely knowledgeable and very easy to speak with regarding any patient questions or concerns.
Sept. 23, 2021
Very thorough. Amazing! She is the best!
Sept. 18, 2021
Dr Maas is such a very caring Dr and her staff all were very nice.
Sept. 3, 2021
Dr Maas, Is wonderful to have as Physicians, she is very caring and always listens to any concerns or questions you may have. While always being very pleasant
Sept. 3, 2021
It was a great experience.
Sept. 2, 2021
Dr Maas is the best!
Aug. 30, 2021
DRM Maas is always thorough, engaging and attentive. I always enjoy my visit with her.
Aug. 27, 2021
I am so pleased with Dr. Maas' care, she is so thorough and answers all my questions to my satisfaction. She is very knowledgeable and I am so lucky to have her for my doctor.
Aug. 9, 2021
Dr. Maas is outstanding. She is very thorough and kind.
Aug. 3, 2021
Dr. Maas is an excellent physician. I live in Florida and would come to any appointment she needed me to have. She is smart, caring. I wish she could take care of all my needs. I am very fortunate she can take care of my endocrinology problems. Dr Maas is the best doctor I have.
July 9, 2021
Dr Maas always treats me with respect and makes me feel she genuinely cares about how I am doing. She never acts rushed and always listens. She's given me excellent care for years.
July 3, 2021
Treated me like a member of the family
June 25, 2021
Always takes the time to answer any of my questions. Listens carefully. Doesn't rush. Very understanding physician.
June 24, 2021
complete trust in her medical judgement
June 23, 2021
she was very thorough and listened to everything I had to say. It was obvious that she studied my file prior to my appointment.
June 18, 2021
Excellent care, respectful, warm, knowledgeable, friendly, approachable and caring. Wonderful Dr!!!
June 18, 2021
provider obviously cares
June 10, 2021
dr Maas so personal that I got comfortable quickly. She listened and answered my questions and more. Her assistant was terrific too.
June 2, 2021
Love the team approach. Dr. Maas is great! Easy to talk to, very knowledgeable, and I always feel she has my best interests at heart.
May 24, 2021
Comprehensive, skilled, and helpful.
Visit for videos, patients reviews and more.