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

Diana L. Maas, MD

Remove | Saved Doctors ()
4.9 (226)
Associate Professor
Accepting New Patients

Call for an appointment

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

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. 226 ratings, 42 reviews
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 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.
May 20, 2021
always on time, very caring
May 20, 2021
Dr. Maas always spends time with me and explains everything. She always says if I think of anything I want to know or have questions about to please call her office.
May 14, 2021
She ALWAYS addresses me with care and respect. ALWAYS listens and explains fully. ALWAYS takes time for me.
May 13, 2021
Dr. Mass is wonderful!
May 8, 2021
Very professional
May 7, 2021
Dr maas has a great attitude, easy to talk with and listens. She is a great Dr.
April 25, 2021
I felt very confident and secure in the care of Dr. Maas. She eased my apprehensions about my health in a difficult time. She is the best doctor that I have ever been to and I have recommended her to friends in the past.
April 22, 2021
Interested in me as an individual as well as patient. Remembers me personally and things about my life.That is important to me.
April 14, 2021
She always takes time to listen.
April 10, 2021
She is a very caring doctor, really listens to what I say. Makes suggestions and explains why. I feel she is being very up front with me.
April 9, 2021
I'm very satisfied with the result of this visit
March 11, 2021
very good visit!
March 5, 2021
I have been seeing Dr. Maas for many years. She is outstanding and very caring. I also send her messages from MyChart and she always has excellent and rapid responses. I am very fortunate to have such an excellent doctor.
March 4, 2021
This was my first visit with DR DIANE MAAS .I had some previous experience with Thyroid doctors that where bad. While she explained things I felt empowered she would ask , LISTEN, then explained. SHE connected dots it was POWERFUL, I had answers finally or I will after test are run (new test) to dig deeper... (filing in the blanks)..Overall great experience with a NEW PROVIDER and hospital.
March 3, 2021
Dr. Diana Maas is a National Treasure
Feb. 25, 2021
overall treatment and caring attitude
Feb. 20, 2021
I have seen Dr. Diana Maas since May 2010. Dr. Maas is absolutely the best...and yes I am very lucky she is my doctor.
Jan. 26, 2021
Dr Maas is one of Froedtert's top physicians. I have been a nurse since 1976 and she by far is absolutely stellar. A shining star!
Jan. 20, 2021
Dr. Maas had reviewed my record thoroughly prior to my appointment. During the visit she took time to solicit my input and verify her understanding of my current problem and past medical history. She demonstrated compassion and confidence about my treatment plan and prognosis. I am so pleased to have such expertise among all my MCW providers!
Jan. 16, 2021
Just a Great Doctor
Dec. 21, 2020
Dr. Maas is always excellent! She gives great advice and encourages me as I try to improve my health!
Dec. 16, 2020
Dr. Maas is knowledgeable, throughout, and patient.
Dec. 11, 2020
Dr. Mass is so caring and easy to talk to. I feel she knows me and will take the needed time to talk. I so appreciate her!
Dec. 10, 2020
Dr Mass is terrific
Dec. 4, 2020
Have a great deal of confidence in Dr. Maas and her colleagues
Nov. 25, 2020
Dr. Maas is an amazing provider. I am fortunate to have her in my care team. She remembers everything I tell her & is an excellent communicator.
Nov. 20, 2020
Dr. Maas is wonderful! She cares and always makes certain that I'm in the best health I can be in. She monitors my lab results and makes recommendations when necessary. I have complete confidence that I have the best care in the world with Dr. Maas.
Nov. 12, 2020
Dr was good. staff was not as good.
Oct. 24, 2020
I really like Dr. Maas and the team and feel fortunate to have them on my team. thanks!
Visit for videos, patients reviews and more.