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Dr. Shannon O'Mahar, MD

Dr. Shannon O'Mahar, MD

Age 43 Medical Oncology F
(4) 4 reviews

Telehealth available

Accepting New Patients


Dr. Shannon O'Mahar, MD is a medical oncology specialist in Madison, WI. Dr. O'Mahar completed a residency at Barnes-Jewish Hospital. She currently practices at Dean Clinic HEM and ONL and is affiliated with Edgerton Hospital And Health Services. She accepts multiple insurance plans. Dr. O'Mahar is board certified in Hematology.


  • University Of Wisconsin Hospital and Clinics, Fellowship Hospital — 2012
  • Barnes-Jewish Hospital, Residency Hospital — 2008
  • Barnes - Jewish Hospital, Internship Hospital — 2006
  • Washington Univ Sch of Med, Medical School — 2005
  • Stanford U, Undergraduate School — 2000

Insurance Accepted

  • Aetna
  • Anthem
  • Anthem Blue Cross Blue Shield
  • AvMed
  • Blue Cross Blue Shield
  • CareFirst Blue Cross Blue Shield
  • Cigna
  • Dean Health Plan, Inc.
  • MultiPlan
  • UnitedHealthCare

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Compare with other Medical Oncology Specialists
Compare Dr. O'Mahar with our nearby Medical Oncology Specialists at Mayo
These providers are on the medical staff of Mayo
These providers are on the medical staff of Mayo.


  1. Dean Clinic HEM and ONL

    1. 1
      Ssm Health Cancer Care
      1200 John Q Hammons Dr Ste 400, Madison, WI 53717 Existing Patients: (608) 410-2700
  1. Dean Clinic Oncology Janesville

    1. 2
      Alliance Healthcare Services Inc.
      3200 E Racine St, Janesville, WI 53546 Existing Patients: (608) 371-8000

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Dr. O'Mahar is the best in the business! She has been absolutely wonderful to myself, and my family and has saved my life. Thank you Dr. O'Mahar!
— Feb 12, 2021
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Dr. Shannon O'Mahar, MD
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Frequently Asked Questions

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Dr. O'Mahar frequently treats Blood Cancers.  

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Hospital Affiliations

  • Edgerton Hospital And Health Services
  • Ssm Health Saint Mary's Hospital Janesville
  • Ssm Health Saint Mary's Hospital Madison
  • Upland Hills Health