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Emergency Medicine

Tom S. Chien, MD

Works at hospitals in South San Francisco, CA · California

Summary

Tom S. Chien, MD (Emergency Medicine) is listed by Medicare at 1 hospital in South San Francisco, CA. NPI 1225205131. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Tom S. Chien, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

Emergency MedicinePrimary specialty
YesAccepts Medicare assignment
21Years since medical school (graduated 2005)
George Washington University School Of MedicineMedical school
MaleGender (as listed)
Permanente Medical Group IncGroup practice

Quick answers

Which hospitals does Tom S. Chien work at?
Medicare's official clinician data lists Tom S. Chien at 1 hospital: Kaiser Foundation Hospital - South San Francisco. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Tom S. Chien see patients?
Medicare's clinician data lists 1 practice location in South San Francisco, CA. Call before your visit to confirm the address.
What is Tom S. Chien's specialty?
Medicare lists Emergency Medicine as the primary specialty.
Does Tom S. Chien accept Medicare assignment?
Yes. Medicare's clinician data says Tom S. Chien 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 Tom S. Chien?
(650) 742-2000, as listed in official Medicare / NPI Registry data.
What is Tom S. Chien's NPI number?
1225205131. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Tom S. Chien works

Medicare's Facility Affiliation Data lists Tom S. Chien at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Tom S. Chien is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Tom S. Chien as a member of this group (CMS data updated 2026-10-02).

  • Permanente Medical Group Inc10,996 clinicians in the group

Specialties

Find other Emergency Medicine doctors in California →

Other emergency medicine doctors in South San Francisco

Clinicians with the same Medicare primary specialty in South San Francisco, CA — not a recommendation.

All emergency medicine doctors in South San Francisco →

Clinician information

CredentialMD
Medical schoolGeorge Washington University School Of Medicine
Graduation year2005
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1225205131
CorrectionsReport 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

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians