DR. MARK THOMAS O'HOLLAREN (M.D.) – Allergy Physician, NPI 1588723787

DR. MARK THOMAS O'HOLLAREN (M.D.) is a healthcare provider. based in Portland, Oregon. specializing in Allergy Physician. They hold the professional credentials M.D.. They hold a License No. 13450 (OR). The NPI Number for DR. MARK THOMAS O'HOLLAREN (M.D.) is 1588723787

Main info

Male
Name
DR. MARK THOMAS O'HOLLAREN (M.D.)
NPI
1588723787
Phone
(503) 228-0155
Address
511 SW 10TH AVE
Enumeration Date
6 December 2006
Last Update Date
8 July 2007
Data current as of
19 May 2026

Profile Insights

NPPES metrics only — not quality of care.

Methodology
Experience52
Completeness75
Years active:19State licenses:1Digital endpointsOther names

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Provider Addresses for DR. MARK THOMAS O'HOLLAREN (M.D.)

  • Vitalize, 511, Southwest 10th Avenue, Portland Downtown, Portland, Metro, Multnomah County, Oregon, 97205, United States

    SUITE 1301

    PORTLAND, OR 972052732

    Phone: (503) 228-0155

    Fax: (503) 226-8342

    Mailing address matches the actual address.

NPPES updates history

No NPPES updates recorded for this provider.

Prescription Activity

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Open Payments (CMS)

No Open Payments data available for this provider.

This can happen when there are no reportable CMS Open Payments records.

Medicare Enrollment & Revalidation

Source: CMS public data · Not endorsed by CMS ·

Educational use only—not medical, billing, or legal advice.

No Medicare enrollment or revalidation data available for this provider in our database.

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Medicare Utilization (FFS)

Source: CMS public data · Not endorsed by CMS · Beneficiary counts under 11 are suppressed in source data ·

Educational use only—not medical, billing, or legal advice.

No Medicare fee-for-service utilization data available for this provider in our database.

Insurance plans in this area (ZIP 97205)

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Reviews

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Frequently asked questions

Is DR. MARK THOMAS O'HOLLAREN (M.D.) listed with a National Provider Identifier?
Yes — DR. MARK THOMAS O'HOLLAREN (M.D.) has NPI 1588723787 on file in the registry.
Active or inactive — what applies to DR. MARK THOMAS O'HOLLAREN (M.D.)?
You should see DR. MARK THOMAS O'HOLLAREN (M.D.) as active in CMS-hosted NPPES data.
What clinical focus is listed for DR. MARK THOMAS O'HOLLAREN (M.D.)?
At a glance, DR. MARK THOMAS O'HOLLAREN (M.D.) is tied to Allergy Physician. Clinical services aligned with this taxonomy classification.
Is DR. MARK THOMAS O'HOLLAREN (M.D.) located near Portland?
DR. MARK THOMAS O'HOLLAREN (M.D.) currently maps to Portland, Oregon in this extract.
Does inactive status remove historical data?
Historical rows can remain visible after status changes — read the dates carefully.

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