Quick answers
- Which hospitals does Tammy Y. Chen work at?
- Medicare's official clinician data lists Tammy Y. Chen at 2 hospitals: Alta Bates Summit Medical Center and Eden Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Tammy Y. Chen see patients?
- Medicare's clinician data lists 1 practice location in Oakland, CA. Call before your visit to confirm the address.
- What is Tammy Y. Chen's specialty?
- Medicare lists Family Practice as the primary specialty.
- Does Tammy Y. Chen accept Medicare assignment?
- Yes. Medicare's clinician data says Tammy Y. Chen 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 Tammy Y. Chen?
- (510) 986-6800, as listed in official Medicare / NPI Registry data.
- What is Tammy Y. Chen's NPI number?
- 1093887721. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Tammy Y. Chen works
Medicare's Facility Affiliation Data lists Tammy Y. Chen at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Alta Bates Summit Medical CenterOakland, CA · Acute Care Hospital · CCN 050043
- Eden Medical CenterCastro Valley, CA · Acute Care Hospital · CCN 050488
Practice locations
Addresses where Tammy Y. Chen is enrolled with Medicare (CMS data updated 2026-10-02).
- 818 Webster StOakland, CA 94607 (510) 986‑6800
Group practices
Medicare enrollment lists Tammy Y. Chen as a member of this group (CMS data updated 2026-10-02).
- Asian Health Services94 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Oakland
Clinicians with the same Medicare primary specialty in Oakland, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1982 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1093887721 |
| 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