Quick answers
- Which hospitals does Robert J. O'Brian work at?
- Medicare's official clinician data lists Robert J. O'Brian at 1 hospital: Frederick Health Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Robert J. O'Brian see patients?
- Medicare's clinician data lists 2 practice locations, including Eldersburg, MD and Bethesda, MD. Call before your visit to confirm the address.
- What is Robert J. O'Brian's specialty?
- Medicare lists Rheumatology as the primary specialty.
- Does Robert J. O'Brian accept Medicare assignment?
- Yes. Medicare's clinician data says Robert J. O'Brian accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Robert J. O'Brian?
- (410) 795-9700, as listed in official Medicare / NPI Registry data.
- What is Robert J. O'Brian's NPI number?
- 1730140724. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Robert J. O'Brian works
Medicare's Facility Affiliation Data lists Robert J. O'Brian at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Frederick Health HospitalFrederick, MD · Acute Care Hospital · CCN 210005
Practice locations
Addresses where Robert J. O'Brian is enrolled with Medicare (CMS data updated 2026-10-02).
- 6190 Georgetown Blvd, Suite 110Eldersburg, MD 21784 (410) 795‑9700
- 6410 Rockledge Dr, Suite 600Bethesda, MD 20817
Group practices
Medicare enrollment lists Robert J. O'Brian as a member of these groups (CMS data updated 2026-10-02).
- Suburban/Nrh Medical Rehabilitation Inc941 clinicians in the group
- Eldersburg Arthritis LLC6 clinicians in the group
Specialties
- Rheumatologyprimary
Other rheumatologists in Maryland
Clinicians with the same Medicare primary specialty in Maryland — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | George Washington University School Of Medicine |
| Graduation year | 1998 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1730140724 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians