Denis O'BrienMD
Denis O'Brien, MD is an Orthopedic Surgery provider in Olney, MD affiliated with 1 ambulatory surgery center in MD, as of July 2026.
- NPI1427053339
- Registered2005
- Centers1
- StateMD
- Class of1983
Case volumes, referral patterns, and payer mix live in DataLily AI Insights.
Ambulatory surgery centers
Centers whose service lines match this provider’s. Affiliations change; verify independently.
Education
Education on record as of August 2026.
Denis O'Brien at a glance
- Provider
- Denis O'Brien
- Credential
- MD
- Specialty
- Orthopedic Surgery
- Procedures
- Orthopedic Surgery CPT codes
- Location
- Olney, MD
- Medical school
- Georgetown University School of Medicine
- Graduated
- 1983
- NPI registered
- 2005
- NPI
- 1427053339
- 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 Denis O'Brien practice?
Denis O'Brien, MD is based in Olney, MD and is affiliated with 1 ambulatory surgery center: Maple Lawn Surgery Center in Fulton, MD. Affiliations reflect the current DataLily AI snapshot (July 2026) and can change.
What is Denis O'Brien's NPI number?
Denis O'Brien's National Provider Identifier (NPI) is 1427053339, registered in 2005. Specialty on record: Orthopedic Surgery; credential MD.
Where did Denis O'Brien go to medical school?
Denis O'Brien, MD attended Georgetown University School of Medicine, graduating in 1983.
How many Orthopedic Surgery providers in Maryland work at ambulatory surgery centers?
140 Orthopedic Surgery surgeons and proceduralists in Maryland are affiliated with ambulatory surgery centers in DataLily AI's current snapshot, Denis O'Brien among them. The Maryland Orthopedic Surgery directory lists each one by city with credential, NPI, and center affiliations.
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