Tricia Merrigan, MD, FACS
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Tricia Merrigan

Tricia Merrigan, MD, FACS

Breast Surgery
5.0 / 5 (Based on 147 Ratings) 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.“

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


February 27, 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 05, 2021
Dr Merrigan is wonderful and makes the experience the best it can be... she has definitely gained our trust and appreciation!
February 04, 2021
Dr. Merrigan is an exceptionally good doctor. I trust her 100% .
January 30, 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 26, 2021
Staffing is top notch! I felt very comfortable with the doctor!
January 08, 2021
We felt valued and cared for!
January 05, 2021
Always treated extremely well at the Prairie Center.
January 03, 2021
Everyone we had contact with was awesome.
December 29, 2020
was a good experience in spite of the diagnosis
December 18, 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 16, 2020
I am very pleased with the care I receive here. Thank You
December 12, 2020
I have nothing but admiration for the entire staff a Avera Breast Health Institute! So much caring is amazing!!
December 09, 2020
Caring, expedient & high quality!
December 08, 2020
Thank you.
December 04, 2020
Dr. Merrigan is fabulous! She always listens and explains things thoroughly. I feel like I'm in very competent hands, and would recommend her to anyone.
November 24, 2020
Dr. Merrigan is the best!
November 13, 2020
The waiting time was short and that is always good!
November 12, 2020
You are the best
November 10, 2020
I am very thankful for the great care given to me at Avera. Everything was done in a timely manner with kindness and professionalism. God bless you all!
October 09, 2020
Very understanding!
September 23, 2020
Dr Tricia Merrigan is easy to personally connect with. I really like her and feel she takes enough time to let you know she cares about you. She has great empathy.
September 19, 2020
Always have a great experience when i am there.
September 07, 2020
Doctor explains everything so well; she makes what can be a scary situation bearable
September 04, 2020
Everyone was really polite and professional
August 28, 2020
Dr Merrigan is terrific....a positive report does help!!!
August 25, 2020
Many kind, caring people work here.
August 25, 2020
Wonderful doctor and fantastic care
August 25, 2020
I am so appreciative to Dr. Merrigan! She is the best!
August 17, 2020
Dr. Merrigan is the best!
August 16, 2020
I feel like the prairie center has the most phenomenal employees from receptionist to doctors
August 15, 2020
All were curtious and respectful
August 11, 2020
Great bunch of gals from receptionist, nurse and doctor!!
August 08, 2020
Thoughtful & caring tremendously!!
August 07, 2020
Got in and out in no time, and everyone was very nice and had smiles on their faces. Nice to see during these times.
August 07, 2020
August 06, 2020
Very compassionate
July 29, 2020
I couldn't ask for better care then I'm getting with Avera!
July 25, 2020
Dr. Merrigan is awesome, and her staff is the best!
July 24, 2020
Cancer care was great
July 24, 2020
The doctor listens
July 15, 2020
July 14, 2020
It's always a great experience when I go to see Dr. Merrigan and the ladies!!
July 12, 2020
Dr. Merrigan and her staff are the best. I have been through many procedures including surgery under her direction and at all times I've been treated in such a caring manner, always professionally, by her and others that work for her. Many thanks to her for her expertise and great "bedside manner".
July 07, 2020
My visit was excellent! I appreciate the fact that they require masks now and took my temperature. Dr. Merrigan is the best!! ??????
July 06, 2020
I love Avera. I love Dr.Merrigan and her staff. I have never had a bad experience.
July 05, 2020
I feel very confident that I will receive the best care and treatment with my doctors at Avera McKennen
June 28, 2020
Dr. Merrigan projects confidence and I really appreciate her care.
June 24, 2020
I'm so glad I found Dr. Merrigan. She did a thorough exam and found the best treatment. I highly recommend her.
June 24, 2020
Very happy with the Dr and staff
June 24, 2020
Dr Merrigan always treats you like an idividual and with repect and dignity! I cannot say enough good things about her and her staff.
June 12, 2020
I feel so extremely fortunate to have Dr. Merrigan as my doctor. She is very skilled, and caring, at the same time. I would recommend her to anyone.
May 30, 2020
Dr Merrigan n her team are amazing. I would highly recommend them to anyone I know that was ever in my situation. God Bless this team of dedication to the health care profession ????
May 30, 2020
Very kind and caring staff at Avera breast center
May 19, 2020
Great doctor and nurse. I am truly blessed!
May 13, 2020
Dr. Merrigan and her staff do an awesome job!

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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