Brian O'Connor, MD
NPI 1174515050 · Medical Oncology Physician · Frederick, MD
Enrolled with Medicare as Practitioner - Hematology/Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Brian O'Connor, MD is a Medical Oncology Physician provider in Frederick, MD (NPI 1174515050).
Provider details
- NPI number
- 1174515050
- Entity type
- Individual
- Primary specialty
- Medical Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- D0031761 (MD)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
2 documented practice locations
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Methotrexate Sodiumbrand: Methotrexate | 12 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Additional practice locations (1)
- 501 W 7th StSuite 1aFrederick, MD 21701-4507Phone: (301) 662-8477Fax: (301) 662-4293
Registry dates
- Enumerated
- 2005-08-17
- Last updated
- 2019-05-15
Frequently asked questions
- What is Brian O'Connor's NPI number?
- Brian O'Connor's National Provider Identifier (NPI) is 1174515050, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Brian O'Connor's specialty?
- Brian O'Connor is listed in the NPPES registry with a primary specialty of Medical Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Brian O'Connor located?
- Brian O'Connor's practice location on file with NPPES is 1562 Opossumtown Pike, Frederick, MD 21702-4337.
- What is Brian O'Connor's phone number?
- The practice phone number listed in the NPPES registry for Brian O'Connor is (301) 662-8477.
- Does Brian O'Connor accept Medicare?
- Brian O'Connor is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Brian O'Connor's NPI active?
- Yes — Brian O'Connor's NPI (1174515050) is active in the NPPES registry as of the last update on 2019-05-15.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.