Quick answers
- Which hospitals does William B. Ershler work at?
- Medicare's official clinician data lists William B. Ershler at 1 hospital: Inova Fairfax Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does William B. Ershler see patients?
- Medicare's clinician data lists 1 practice location in Falls Church, VA. Call before your visit to confirm the address.
- What is William B. Ershler's specialty?
- Medicare lists Internal Medicine as the primary specialty, and also Hematology/Oncology and Medical Oncology.
- Does William B. Ershler accept Medicare assignment?
- Yes. Medicare's clinician data says William B. Ershler 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 William B. Ershler?
- (703) 776-4001, as listed in official Medicare / NPI Registry data.
- What is William B. Ershler's NPI number?
- 1669496881. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where William B. Ershler works
Medicare's Facility Affiliation Data lists William B. Ershler at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Inova Fairfax HospitalFalls Church, VA · Acute Care Hospital · CCN 490063
Practice locations
Addresses where William B. Ershler is enrolled with Medicare (CMS data updated 2026-10-02).
- 3300 Gallows RdFalls Church, VA 22042 (703) 776‑4001
Group practices
Medicare enrollment lists William B. Ershler as a member of this group (CMS data updated 2026-10-02).
- Inova Health Care Services1,817 clinicians in the group
Specialties
- Internal Medicineprimary
- Hematology/Oncologyalso
- Medical Oncologyalso
Other internal medicine doctors in Falls Church
Clinicians with the same Medicare primary specialty in Falls Church, VA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | State University Of Ny Upstate Medical University |
| Graduation year | 1974 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1669496881 |
| 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