Quick answers
- Which hospitals does Robert B. Mason Ii work at?
- Medicare's official clinician data lists Robert B. Mason Ii at 1 hospital: MedStar Washington Hospital Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Robert B. Mason Ii see patients?
- Medicare's clinician data lists 1 practice location in Washington, DC. Call before your visit to confirm the address.
- What is Robert B. Mason Ii's specialty?
- Medicare lists Neurosurgery as the primary specialty.
- Does Robert B. Mason Ii accept Medicare assignment?
- Yes. Medicare's clinician data says Robert B. Mason Ii 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 B. Mason Ii?
- (202) 429-2401, as listed in official Medicare / NPI Registry data.
- What is Robert B. Mason Ii's NPI number?
- 1639195795. 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 B. Mason Ii works
Medicare's Facility Affiliation Data lists Robert B. Mason Ii at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- MedStar Washington Hospital CenterWashington, DC · Acute Care Hospital · CCN 090011
Practice locations
Addresses where Robert B. Mason Ii is enrolled with Medicare (CMS data updated 2026-10-02).
- 1145 19th St NW, 311 Mmg at 19th Street NWWashington, DC 20036 (202) 429‑2401
Group practices
Medicare enrollment lists Robert B. Mason Ii as a member of this group (CMS data updated 2026-10-02).
- MedStar Medical Group II LLC3,767 clinicians in the group
Specialties
- Neurosurgeryprimary
Other neurosurgeons in Washington
Clinicians with the same Medicare primary specialty in Washington, DC — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Uniformed Services Uhs Fe Hebert School Of Med |
| Graduation year | 1990 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1639195795 |
| 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