A medical license is required for a doctor to practice medicine in a particular state. Requirements vary by state but most require, at a minimum, post-graduate training in the doctor’s specific specialty. An NPI number is a national identifier unique to an individual health care provider and is managed by the Center for Medicare & Medicaid Services (CMS).
Learn more about Dr. Mark O'Hollaren:
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- Currently 4 of 4 stars
The overall average patient rating of Dr. Mark O'Hollaren is Excellent.
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Specialties & Research
Dr. Mark O'Hollaren, MD is board certified in Allergy & Immunology and Internal Medicine.
- He has special expertise in 3 areas:
- Food Allergy (Hypersensitivity)
- Nasal Allergy (Rhinitis)
Education & Awards
Dr. O'Hollaren graduated from Oregon Health & Science University, Portland. He has 2 awards.
Dr. O'Hollaren has 3 hospital affiliations:
- Providence St Vincent Medical Center
- Oregon Health & Science Univ H, Portland, Or
- Oregon Health Science University
Accepted Insurance Plans
Dr. O'Hollaren accepts these health insurances in at least one office:
- Providence Health Plan - 21 plans
- United Healthcare - 12 plans
- Regence Blue Cross Blue Shield - 6 plans
- Great-West Healthcare - 2 plans
- ODS Health Plans - 4 plans
- Evercare - 1 plan
- Humana - 6 plans
- Cigna - 4 plans
- Aetna - 2 plans