Quick answers
- Which hospitals does Alexander S. Mark work at?
- Medicare's official clinician data lists Alexander S. Mark at 5 hospitals: MedStar Franklin Square Medical Center, MedStar Good Samaritan Hospital, MedStar Harbor Hospital, MedStar Saint Mary's Hospital and MedStar Southern Maryland Hospital Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Alexander S. Mark see patients?
- Medicare's clinician data lists 6 practice locations, including Waldorf, MD, Washington, DC and Hollywood, MD. Call before your visit to confirm the address.
- What is Alexander S. Mark's specialty?
- Medicare lists Diagnostic Radiology as the primary specialty.
- Does Alexander S. Mark accept Medicare assignment?
- Yes. Medicare's clinician data says Alexander S. Mark 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 Alexander S. Mark?
- (301) 373-7900, as listed in official Medicare / NPI Registry data.
- What is Alexander S. Mark's NPI number?
- 1770573388. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Alexander S. Mark works
Medicare's Facility Affiliation Data lists Alexander S. Mark at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- MedStar Franklin Square Medical CenterRosedale, MD · Acute Care Hospital · CCN 210015
- MedStar Good Samaritan HospitalBaltimore, MD · Acute Care Hospital · CCN 210056
- MedStar Harbor HospitalBaltimore, MD · Acute Care Hospital · CCN 210034
- MedStar Saint Mary's HospitalLeonardtown, MD · Acute Care Hospital · CCN 210028
- MedStar Southern Maryland Hospital CenterClinton, MD · Acute Care Hospital · CCN 210062
Practice locations
Addresses where Alexander S. Mark is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 6; the Medicare profile lists all.
- 10 Saint Patricks DrWaldorf, MD 20603 (301) 373‑7900
- 110 Irving St NWWashington, DC 20010 (202) 877‑7000
- 24035 Three Notch RdHollywood, MD 20636 (301) 373‑7900
- 25500 Point Lookout RdLeonardtown, MD 20650 (240) 434‑4088
- 3202 Tower Oaks BlvdRockville, MD 20852 (301) 657‑2444
Group practices
Medicare enrollment lists Alexander S. Mark as a member of these groups (CMS data updated 2026-10-02).
- MedStar Medical Group II LLC3,767 clinicians in the group
- MedStar Medical Group - Southern Maryland LLC245 clinicians in the group
- Physician Imaging of Washington Hospital Center LLC104 clinicians in the group
Specialties
- Diagnostic Radiologyprimary
Other radiologists in Waldorf
Clinicians with the same Medicare primary specialty in Waldorf, MD — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1982 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1770573388 |
| 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