Quick answers
- Which hospitals does William A. Lee work at?
- Medicare's official clinician data lists William A. Lee at 1 hospital: Adventist Health Simi Valley. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does William A. Lee see patients?
- Medicare's clinician data lists 1 practice location in Simi Valley, CA. Call before your visit to confirm the address.
- What is William A. Lee's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does William A. Lee accept Medicare assignment?
- Yes. Medicare's clinician data says William A. Lee 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 A. Lee?
- (805) 210-7280, as listed in official Medicare / NPI Registry data.
- What is William A. Lee's NPI number?
- 1619960705. 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 A. Lee works
Medicare's Facility Affiliation Data lists William A. Lee at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Adventist Health Simi ValleySimi Valley, CA · Acute Care Hospital · CCN 050236
Practice locations
Addresses where William A. Lee is enrolled with Medicare (CMS data updated 2026-10-02).
- 2755 Alamo St, Suite 101Simi Valley, CA 93065 (805) 210‑7280
Group practices
Medicare enrollment lists William A. Lee as a member of this group (CMS data updated 2026-10-02).
- Simi Medical Group, Inc3 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Simi Valley
Clinicians with the same Medicare primary specialty in Simi Valley, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2001 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1619960705 |
| 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