Quick answers
- Which hospitals does Stephen J. Antonik work at?
- Medicare's official clinician data lists Stephen J. Antonik at 2 hospitals: Inova Loudoun Hospital and Reston Hospital Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Stephen J. Antonik see patients?
- Medicare's clinician data lists 2 practice locations, including Reston, VA and Leesburg, VA. Call before your visit to confirm the address.
- What is Stephen J. Antonik's specialty?
- Medicare lists Gastroenterology as the primary specialty.
- Does Stephen J. Antonik accept Medicare assignment?
- Yes. Medicare's clinician data says Stephen J. Antonik 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 Stephen J. Antonik?
- (703) 689-9019, as listed in official Medicare / NPI Registry data.
- What is Stephen J. Antonik's NPI number?
- 1770567257. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Stephen J. Antonik works
Medicare's Facility Affiliation Data lists Stephen J. Antonik at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Inova Loudoun HospitalLeesburg, VA · Acute Care Hospital · CCN 490043
- Reston Hospital CenterReston, VA · Acute Care Hospital · CCN 490107
Practice locations
Addresses where Stephen J. Antonik is enrolled with Medicare (CMS data updated 2026-10-02).
- 1850 Town Ctr PkwyReston, VA 20190 (703) 689‑9019
- 19500 Sandridge Way, Suite 470Leesburg, VA 20176 (703) 771‑9001
Specialties
- Gastroenterologyprimary
Other gastroenterologists in Reston
Clinicians with the same Medicare primary specialty in Reston, VA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Loyola University Of Chicago, Stritch School Of Medicine |
| Graduation year | 2002 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1770567257 |
| 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