Gerald Diaz, M.D.
NPI 1669784443 · Internal Medicine Physician · San Jose, CA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gerald Diaz, M.D. is a Internal Medicine Physician provider in San Jose, CA (NPI 1669784443).
Provider details
- NPI number
- 1669784443
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- A126359 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
15 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
2 documented practice locations
- Medicare service volume (vs. specialty peers)28% of score
817 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 643 | $89 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 108 | $132 |
| Initial Hospital Care With Straightforward Or Low-Level Medical Decision Making, If Using Time, at Least 55 Minutes99222 | 42 | $147 |
| Subsequent Hospital Care With Straightforward Or Low Level of Medical Decision Making, Per Day, If Using Time, at Least 25 Minutes99231 | 24 | $55 |
Typical Medicare-allowed amounts for these services range $55–$147 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Apixabanbrand: Eliquis | 22 | 13 |
| Pantoprazole Sodium | 16 | 11 |
| Atorvastatin Calcium | 15 | — |
| Metoprolol Succinate | 12 | — |
| Tamsulosin Hcl | 11 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means , never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Additional practice locations (1)
- 2799 W. Grand BoulevardHenry Ford HospitalDetroit, MI 48202Phone: (800) 436-7936
Registry dates
- Enumerated
- 2010-07-08
- Last updated
- 2021-03-18
- Certified
- 2021-03-18
Frequently asked questions
- What is Gerald Diaz's NPI number?
- Gerald Diaz's National Provider Identifier (NPI) is 1669784443, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gerald Diaz's specialty?
- Gerald Diaz is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Gerald Diaz located?
- Gerald Diaz's practice location on file with NPPES is 751 S Bascom Ave, San Jose, CA 95128-2699.
- What is Gerald Diaz's phone number?
- The practice phone number listed in the NPPES registry for Gerald Diaz is (408) 368-6498.
- Does Gerald Diaz accept Medicare?
- Gerald Diaz is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gerald Diaz's NPI active?
- Yes — Gerald Diaz's NPI (1669784443) is active in the NPPES registry as of the last update on 2021-03-18.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.