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Thomas J. Desmarais

Thomas J. Desmarais, MD

Vascular Surgery

Accepting New Patients
Need help scheduling? Call 406-238-6820

Highlights

Age Groups Seen

  • Adult 19-64
  • Older Adult >65

Gender

Male

Hospital Affiliation

  • Holy Rosary Hospital
  • St. Vincent Regional Hospital

About Thomas J. Desmarais

About The Provider

Arizona native Dr. Desmarais was drawn to Vascular Surgery for its wide breadth and long-term patients. He provides a level of service that he would expect for his own family members. His philosophy of care is patient centered and evidence based.

Dr. Desmarais looks forward to meaningful interactions with patients whether in the clinic or operating room - and in improving symptoms or preventing complications of vascular disease.

He has many family members locally, and spent a great deal of time during his childhood in Montana. He is pleased to return to Big Sky Country for its friendly and hard-working people, beautiful scenery and outdoor opportunities. When not caring for patients, Dr. Desmarais enjoys backpacking, skiing, cycling and spending time with his family. 

Video

Locations

  1. Intermountain Health Heart & Vascular - Downtown Cardiac & Vascular Surgery
  2. Intermountain Health Heart & Vascular - Gallatin Thoracic & Vascular Surgery Outreach

Expertise

Education

  • Residency: Washington University School of Medicine, Surgery, Vascular Surgery, 2019
  • Residency: None, Vascular Surgery, 2019
  • Medical School: Geisel School Of Medicine At Dartmouth, 2014

Board Certifications

  • American Board of Surgery, 2021

Insurance

Please contact the doctor's office directly to confirm acceptance of insurance.
Search plans
  • 6 Degrees Health
  • Aetna
  • Alignetworks
  • Allegiance Provider Direct
  • Americas Choice Provider Network
  • Banner Health System
  • BCBS
  • Cigna
  • City of Billings Employee Health Plan
  • Community Health Network
  • FedMed Network
  • First Choice Health Network
  • First Choice of the Midwest
  • First Health/Coventry
  • Fortified Provider Network
  • Humana
  • Humana Medicare Advantage
  • Interwest
  • Logistics Health Incorporated
  • Montana Health Systems
  • Mountain Health Co-op
  • Pacific Steel & Recycling
  • PacificSource
  • Preferred One
  • Sibanye Stillwater Health Partners
  • Three Rivers Provider Network
  • Tricare
  • TriWest
  • United Healthcare
  • VA Montana Health System

Ratings & Reviews

5 out of 5

79 ratings, 11 reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Search reviews
    5 out of 5 stars
    Reviewed on 1/21/2026

    Very educated and explains things to help you understand. Soft spoken and very polite. Glad he's watching out for me🙏

    5 out of 5 stars
    Reviewed on 12/21/2025

    Excellent

    5 out of 5 stars
    Reviewed on 12/12/2025

    Very knowledgeable, listened to my concerns, had answers for me. Thank you Dr. Desmarais.

    5 out of 5 stars
    Reviewed on 12/11/2025

    I will be back.

    5 out of 5 stars
    Reviewed on 11/29/2025

    Dr. Descartes went out of his way to help set up the teleconference, creating the least hardship on me.

    5 out of 5 stars
    Reviewed on 11/2/2025

    Just like to say thank you for your help

    5 out of 5 stars
    Reviewed on 10/3/2025

    He’s a very personable doctor who really cares

    5 out of 5 stars
    Reviewed on 10/2/2025

    Easy to talk with.

    5 out of 5 stars
    Reviewed on 9/27/2025

    He’s done great work on me and is a very compassionate surgeon I really like him. He is top of the line can’t get better than he is

    5 out of 5 stars
    Reviewed on 8/17/2025

    He is one of a kind. He's informative and caring. A great doctor to have on my team

    5 out of 5 stars
    Reviewed on 7/27/2025

    Dr Desmarais was very good told me all I needed to know and did a wonderful job with the surgery! I’m very pleased!