Quick answers
- Which hospitals does Alejandro E. Diaz work at?
- Medicare's official clinician data lists Alejandro E. Diaz at 2 hospitals: Alameda Hospital and Highland Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Alejandro E. Diaz see patients?
- Medicare's clinician data lists 1 practice location in Oakland, CA. Call before your visit to confirm the address.
- What is Alejandro E. Diaz's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Alejandro E. Diaz accept Medicare assignment?
- Yes. Medicare's clinician data says Alejandro E. Diaz 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 Alejandro E. Diaz?
- (510) 437-4800, as listed in official Medicare / NPI Registry data.
- What is Alejandro E. Diaz's NPI number?
- 1437591104. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Alejandro E. Diaz works
Medicare's Facility Affiliation Data lists Alejandro E. Diaz at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Alameda HospitalAlameda, CA · Acute Care Hospital · CCN 050211
- Highland HospitalOakland, CA · Acute Care Hospital · CCN 050320
Practice locations
Addresses where Alejandro E. Diaz is enrolled with Medicare (CMS data updated 2026-10-02).
- 1411 E 31st StOakland, CA 94602 (510) 437‑4800
Group practices
Medicare enrollment lists Alejandro E. Diaz as a member of this group (CMS data updated 2026-10-02).
- Alameda Health System601 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Oakland
Clinicians with the same Medicare primary specialty in Oakland, CA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 2012 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1437591104 |
| 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