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Tricia Merrigan

Tricia Merrigan, MD, FACS

Breast Surgery
5.0 / 5 (Based on 213 Ratings) Read Reviews | Learn More

“It’s important for me to develop a relationship with each patient. I take time to help her understand what’s happening and hope she feels like she’s involved in the process, comfortable with her treatment and included at all times.“

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Office Information

About Me

If you or a loved one receives a breast cancer diagnosis, count on Tricia Merrigan, MD, FACS, for experienced and specialized breast surgery. Dr. Merrigan is a fellowship-trained and board-certified breast surgeon at Avera Medical Group Comprehensive Breast Care in Sioux Falls, SD.

Innovative Breast Cancer Surgical Procedures

Providing an effective breast cancer surgery is Dr. Merrigan’s first priority. She also strives to give women the best cosmetic result possible. She achieves this through specialized training in surgical procedures such as:

  • Electron-based intraoperative radiation therapy (IORT) – Includes radiation during surgery which may eliminate the need for additional radiation or shorten the course of radiation
  • Oncoplasty – Combines techniques for removing cancer along with plastic surgery methods to improve the appearance of breasts
  • Lumpectomy – Conserves the breasts while providing the same recurrence prevention as mastectomy
  • Nipple-sparing mastectomy – Preserves the nipple and skin of the breast for future reconstruction
  • Hidden Scar™ – Removes the tumor and a slight amount of surrounding tissue through a small incision

Dr. Merrigan was the first surgeon in South Dakota, Minnesota, Nebraska and North Dakota to receive Hidden Scar™ certification. "I’m dedicated to this approach," she says. "It takes a little extra effort and time to avoid making scars on the breast so that they heal nicely, but is well worth it for my patients."

Compassionate, Holistic Care for Women

"I really believe in our mission – caring for the patient as a whole," she adds. "Treating breast cancer at Avera is all about providing a team approach to care for the whole patient. It’s all about doing what’s best for each patient."

Active Lifestyle

In her free time, Dr. Merrigan likes to play games, go camping and enjoy the outdoors with her family. She also enjoys riding and showing horses.



University of South Dakota Sanford School of Medicine, Vermillion


General Surgery; Iowa Methodist Medical Center, Des Moines


Breast Surgery Oncology; Akron General Medical Center, Accredited by the Society of Surgical Oncology


American Board of Surgery


September 25, 2022
She listened to me about thoughts and willing to work with me about my treatment. I will go with what she suggests is best for me in the long run. She is very open mind and truly cares about her patients.
September 09, 2022
Everyone respected and care about how I felt
August 22, 2022
I rate Dr. Merrigan and her staff a 10 on a scale of 1 to 10. Can't say enough good about the care and advice they have given me. They just do it right from start to finish as far as my appointments, care and surgery.
August 19, 2022
Dr. Merrigan is the best! She treated me four years ago and I have complete confidence in her.
August 15, 2022
Dr.Merrigan and her staff are outstanding! Dr. Merrigan is certainly one of whom I would consider the best of the best. She is able to explain things in terms easy to understand. It is easy to recognize her passion for what she does. In addition she has the empathy and compassion needed to direct and guide you through the treatment process.
July 27, 2022
Dr Merrigan spent ample time with me, discussing my concerns, options and any further treatment needs. She has been a very professional, patient Advocate for me on this health care journey. She's awesome!
July 22, 2022
June 07, 2022
Excellent care
April 15, 2022
I would definitely recommend her to someone else. Dr Merrigan was very good at describing my situation and options.
February 27, 2022
She explained my options in detail, answered my questions throughly and seemed like she cared about her patients outcome
February 11, 2022
We have been grateful for Dr Merrigans expertise, ability to communicate clearly, understanding of our concerns, listening and explaining.
January 19, 2022
I honestly can't think of a better place for me to have gone throughout my latest cancer journey. Everyone is/was professional, compassionate, and helpful.... Always.
January 15, 2022
Dr makes sure all our questions are answered. Doesn't seem to be in a rush when meeting with us.
September 28, 2021
Very pleasant atmosphere and understanding employees
September 21, 2021
Dr. Merrigan is a true professional and The nurse is pretty awesome as well.
September 21, 2021
Dr. Merrigan explained all of my options thoroughly including pros/cons. Was very professional and took time to listen to me, not just talk to me. Made me feel comfortable with the consult
September 21, 2021
Everyone was very caring and knowledgeable.
September 07, 2021
I also had appointment in the breast center and the nurse and doctor there were excellent also. I would recommend anyone to go there
September 07, 2021
Everyone at this facility is so nice and willing to help when needed!!!
August 31, 2021
I liked everything about this Care center
August 31, 2021
Dr Tricia Merrigan is beyond the greatest!!
August 31, 2021
I feel my care is always the best when I have an appointment.
August 24, 2021
Very nice staff and doctor.
August 24, 2021
The best place if you need care!
August 17, 2021
They are so friendly and seriously caring. Such a relief, you can feel the good care you are in.
August 17, 2021
Dr. was well knowledged and I felt comfortable with her.
August 17, 2021
Thank you for excellent care!!!
August 03, 2021
Dr. Merrigan and her team are awesome!!!
August 03, 2021
I have always felt welcome there and had such great care and treatment. All very friendly and love Merrigan
August 03, 2021
Dr. Merrigan and her staff are the best! I feel that Dr. Merrigan saved my life by ordering tests that detected my 2nd breast cancer early enough that I was able to have it removed before anything spread. Her caring concern and calm manner always gave me hope. She also is an excellent surgeon. Many thanks to her and her staff for their excellent care.
July 27, 2021
I get the greatest care here!
July 13, 2021
Everyone was wonderful!! I don't go anywhere else. Only AVERA!
July 06, 2021
June 22, 2021
Great place.
June 22, 2021
Absolutely EVERYONE from the time I walked in the doors was just top notch!
June 15, 2021
I appreciate Dr. Merrigan so much! She is pleasant, takes time with me, and is reassuring. The receptionist at the front desk is also so pleasant, friendly, and inviting. Dr. Merrigan's nurse does a good job too. I am thankful to see the same people each time I come!
June 15, 2021
I have always been happy with the care I received with Dr. Merrigan and the entire staff.
June 15, 2021
Always feel informed and well cared for
June 08, 2021
I think we are incredibly fortunate to have access to such high quality medical care in a town the size of Yankton.
May 25, 2021
Dr. Merrigan is very approachable, caring, compassionate & dedicated professional who has her patients needs as her priority!
May 18, 2021
Everyone has been wonderful. They realize that you really dont want to have to be there but do there best to make you comfortable and meet your needs.
April 27, 2021
went well
April 20, 2021
Everyone was very helpful. Very pleased.
April 13, 2021
Everyone was very helpful and provided necessary information.
April 06, 2021
it was a great visit as always
March 30, 2021
all staff where great!
March 23, 2021
It is wonderful to be treated as a person and listened to attentively. Dr Merrigan really cares about her patients and makes a great connection!
March 02, 2021
Dr Merrigan and staff are wonderful people! They have always treated me with outmost respect and every case to them is special. I am moving on to survivorship clinic!!! I will miss them but so grateful
February 09, 2021
Dr. Merrigan is an exceptionally good doctor. I trust her 100% .
February 09, 2021
Dr Merrigan is wonderful and makes the experience the best it can be... she has definitely gained our trust and appreciation!
February 02, 2021
Staffing is top notch! I felt very comfortable with the doctor!
February 02, 2021
The nurse always remembers me and that makes me feel special. Dr. Merrigan also makes it seem like weeks between appts, not 12 months. I truly appreciate their care.
January 12, 2021
Always treated extremely well at the Prairie Center.
January 12, 2021
We felt valued and cared for!
January 05, 2021
was a good experience in spite of the diagnosis
January 05, 2021
Everyone we had contact with was awesome.
December 22, 2020
I am very pleased with the care I receive here. Thank You
December 22, 2020
These people in this office have alway been the most friendly and kindest people every single time! Every single one of them! They make you feel amazing!
December 15, 2020
Thank you.
December 15, 2020
Caring, expedient & high quality!
December 15, 2020
I have nothing but admiration for the entire staff a Avera Breast Health Institute! So much caring is amazing!!

This directory contains information about the provider members of Independent Health Care Associates, Avera Health and all Avera entities, members of the Avera Medical Group, and employed select providers with Avera McKennan, Sioux Falls, SD and Avera Marshall, Marshall, MN and physicians with hospital privileges at Avera St. Luke's, Aberdeen, SD; Avera Sacred Heart, Yankton, SD; Avera Queen of Peace, Mitchell, SD; Avera St. Mary's, Pierre, SD.

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