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Justin F Gainor

Justin F Gainor, MD

HematologyMedical Oncology

Mass General Brigham

Highlights

Age Groups Seen

  • Adults

Languages

  • English

Gender

Male

Locations

  1. Mass General Brigham Cancer Institute Center for Thoracic Oncology Medical Oncology at Boston
    • 32 Fruit Street, Yawkey Building, 7th Floor, Suite 7b, Boston, MA 02114
    • Get Directions

Expertise

Education

  • Fellowship: Dana Farber Cancer Institute / Brigham & Women's Hospital, Hematology & Medical Oncology (Internal Medicine), 2013
  • Residency: Massachusetts General Hospital, Internal Medicine, 2011
  • Medical Education: Harvard Medical School, 2008

Board Certifications

  • Medical Oncology: American Board of Internal Medicine, 2013

Insurance

Search plans
  • Aetna
  • Beech Street
  • Blue Cross Blue Shield
  • Blue Cross Blue Shield - Indemnity
  • Blue Cross Blue Shield Medicare
  • Cigna
  • Commonwealth Care Alliance
  • Coventry
  • Fallon Health
  • Harvard Pilgrim Health Care
  • Humana
  • Maine Community Health Options
  • Mass General Brigham Health Plan
  • MassHealth
  • Medicaid ME
  • Medicaid NH
  • Medicaid RI
  • Medicaid VT
  • Medicare
  • Medicare ACO
  • Multiplan
  • Railroad Medicare
  • Senior Whole Health
  • TriCare
  • Tufts Health Plan
  • Tufts Medicare Preferred
  • United Health Care
  • Wellpoint
  • WellSense
  • WellSense NH

Ratings & Reviews

4.9 out of 5

83 ratings, 28 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.

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  • Reviewed on 7/5/2026

    Justin Gainor the doctor was terrific. Very knowledgeable. Spent this time with me. Explain things to me. I believe that he when I left there. Not only a good doctor but a caring person and that meant a lot to me. He was a terrific guy and Doctor. I can't say enough about him

  • Reviewed on 7/3/2026

    Dr. Gainor is very kind, considerate, and very generous with his time. He's explicit. He doesn't sugarcoat things. He tells me the truth. I appreciate him.

  • Reviewed on 6/27/2026

    Very good has a great bed side manner

  • Reviewed on 6/26/2026

    The oncologist was very positive and optimistic which makes it easier or me to keep my health

  • Reviewed on 6/21/2026

    Great experience!!

  • Reviewed on 6/16/2026

    Dr. Gainor was very thorough and clear with his explanations. It has been a pleasure working with him.

  • Reviewed on 6/9/2026

    My doctor is a caring and informed provider. He is interested in the whole patient, not just the issue I am seeing him for. I trust him with my care.

  • Reviewed on 5/12/2026

    Dr Gainor and Dr [redacted] both needed more information to evaluate my condition. They both were very professional. I felt a sense of relief that they will take care of me. I left there with hope.

  • Reviewed on 5/7/2026

    I feel so lucky to have the care that I do from Dr. Gainor and Dr. [redacted] and their team.

  • Reviewed on 5/7/2026

    Dr. Gainor is a great doctor

  • Reviewed on 5/6/2026

    I am very happy with my care provider. The day I had my consultation with him and some of his team I was very happy knowing that he would be my care provider.

  • Reviewed on 3/18/2026

    He was easy to talk too and understood me

  • Reviewed on 3/4/2026

    This care provider is very respectful, courteous and in tune with your needs

  • Reviewed on 2/26/2026

    For the past 10 years I have felt comfortable, confident & well taken care of by Dr Gainor and his staff.

  • Reviewed on 2/18/2026

    The provider is exceptional. He has a wealth of knowledge which he presents with a gentle manner. This provider is someone that is a compliment to MGH

  • Reviewed on 2/10/2026

    I feel very lucky to have the team at MGB

  • Reviewed on 1/30/2026

    I just wanted to say my experience with this provider and my doctor, they're very, how do I say that? They're just wonderful, wonderful people. I'm very comfortable with my doctor and with the nurse. Always have been, I have no complaints with any of them. They're great, both of them. All right, thank you. And again, I have the best providers, best doctors in that hospital. I love that hospital. Thank you.

  • Reviewed on 1/28/2026

    Top notch

  • Reviewed on 1/28/2026

    I'm extremely happy with him, he answers all my questions, and never rushes through our visit.

  • Reviewed on 1/8/2026

    Very compassionate, helpful and knowledgeable

  • Reviewed on 12/31/2025

    Dr. Gainor was compassionate, caring and took the time to explain my diagnosis in a way that is easy to understand. He listened to us and responded to all of our questions and concerns. He spent as much time with us as needed to address everything we asked. I can't recommend Dr. Gainor enough. I feel incredibly grateful for him and his whole care team who communicates with us and makes us feel like I am important person, not just another patient. In this world. this is priceless and we appreciate him!! Thank you Dr. Gainor!

  • Reviewed on 12/24/2025

    I go to the mass General every day for treatment and I get the best care possible kind and considerate staff

  • Reviewed on 12/11/2025

    Dr. Gainor explained things very much in depth and in a way that I had not heard before and I appreciated him going into more detail than I had heard before.

  • Reviewed on 11/28/2025

    Dr. Gainor is thorough, easy to talk to and explains things very well.

  • Reviewed on 10/9/2025

    Dr. Gainor definitely deserves the name doctor. He has treated my cancer for a couple of years and since it has been gone he is doing a great job of keeping on top of the situation. I have no worries at all concerning him or the office he works in. That includes nurses and other support staff.

  • Reviewed on 9/28/2025

    I am very, very happy with Dr. Gainor and the rest of the team. Everyone put my mind at ease.

  • Reviewed on 9/10/2025

    Talked in layman's terms to define medical terms

  • Reviewed on 8/28/2025

    Because of Dr Gainor, I'm living to play with my 4GrandChildren with my 5th one on the way. Each day is a blessing.