John OholleranMD
General Surgery·Oregon City, OR
John Oholleran, MD is a General Surgery provider in Oregon City, OR affiliated with 2 ambulatory surgery centers across CA and OR, as of July 2026.
- NPI1912007220
- Registered2006
- Centers2
- StatesCA · OR
- Class of1987
Case volumes, referral patterns, and payer mix live in DataLily AI Insights.
Ambulatory surgery centers
Centers whose service lines match this provider’s: 1 in CA, 1 in OR. Affiliations change; verify independently.
Education
Education on record as of August 2026.
John Oholleran at a glance
- Provider
- John Oholleran
- Credential
- MD
- Specialty
- General Surgery
- Procedures
- General Surgery CPT codes
- Location
- Oregon City, OR
- Medical school
- University of Nebraska College of Medicine
- Graduated
- 1987
- NPI registered
- 2006
- NPI
- 1912007220
- Snapshot
- July 2026
Identity, specialty, and affiliations change over time. This is not an endorsement, and not clinical, billing, or legal advice. Providers may request corrections at founders@datalilyai.com. Read the DataLily AI data methodology.
Questions
Where does John Oholleran practice?
John Oholleran, MD is based in Oregon City, OR and is affiliated with 2 ambulatory surgery centers: Surgecenter Of Palo Alto in Palo Alto, CA and Plaza Ambulatory Surgery Center LLC in Portland, OR. Affiliations reflect the current DataLily AI snapshot (July 2026) and can change.
What is John Oholleran's NPI number?
John Oholleran's National Provider Identifier (NPI) is 1912007220, registered in 2006. Specialty on record: General Surgery; credential MD.
Where did John Oholleran go to medical school?
John Oholleran, MD attended University of Nebraska College of Medicine, graduating in 1987.
How many General Surgery providers in Oregon work at ambulatory surgery centers?
48 General Surgery surgeons and proceduralists in Oregon are affiliated with ambulatory surgery centers in DataLily AI's current snapshot, John Oholleran among them. The Oregon General Surgery directory lists each one by city with credential, NPI, and center affiliations.
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