Quick answers
- Which hospitals does William C. Sim work at?
- Medicare's official clinician data lists William C. Sim at 3 hospitals: Memorialcare Long Beach Medical Center, PIH Health Downey Hospital and PIH Health Hospital-Whittier. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does William C. Sim see patients?
- Medicare's clinician data lists 1 practice location in Downey, CA. Call before your visit to confirm the address.
- What is William C. Sim's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does William C. Sim accept Medicare assignment?
- Yes. Medicare's clinician data says William C. Sim 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.
- Does William C. Sim offer telehealth?
- Medicare's clinician data says William C. Sim offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for William C. Sim?
- (562) 806-0874, as listed in official Medicare / NPI Registry data.
- What is William C. Sim's NPI number?
- 1437256906. 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 C. Sim works
Medicare's Facility Affiliation Data lists William C. Sim at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Memorialcare Long Beach Medical CenterLong Beach, CA · Acute Care Hospital · CCN 050485
- PIH Health Downey HospitalDowney, CA · Acute Care Hospital · CCN 050393
- PIH Health Hospital-WhittierWhittier, CA · Acute Care Hospital · CCN 050169
Practice locations
Addresses where William C. Sim is enrolled with Medicare (CMS data updated 2026-10-02).
- 11480 Brookshire Ave, Suite 200Downey, CA 90241 (562) 806‑0874
Group practices
Medicare enrollment lists William C. Sim as a member of this group (CMS data updated 2026-10-02).
- Frischer Medical Group Inc4 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Downey
Clinicians with the same Medicare primary specialty in Downey, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Stanford University School Of Medicine |
| Graduation year | 1990 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1437256906 |
| 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