Melissa Martinez-Diaz, MD
NPI 1255350427 · Internal Medicine Physician · San Antonio, TX
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Melissa Martinez-Diaz, MD is a Internal Medicine Physician provider in San Antonio, TX (NPI 1255350427).
Provider details
- NPI number
- 1255350427
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- M0812 (TX)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
108 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
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 .
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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 65 | $122 |
| Blood Glucose (sugar) Test Performed By Hand-Held Instrument82962 | 32 | $3 |
| Administration of Influenza Virus VaccineG0008 | 11 | $31 |
Typical Medicare-allowed amounts for these services range $3–$122 (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 · 140 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rosuvastatin Calcium | 665 | 224 |
| Losartan Potassium | 561 | 184 |
| Atorvastatin Calcium | 557 | 180 |
| Metformin Hcl | 459 | 140 |
| Lisinopril | 390 | 121 |
| Gabapentin | 361 | 145 |
| Amlodipine Besylate |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$813 across 33 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-07-19
- Last updated
- 2022-01-07
- Certified
- 2022-01-07
Frequently asked questions
- What is Melissa Martinez-Diaz's NPI number?
- Melissa Martinez-Diaz's National Provider Identifier (NPI) is 1255350427, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Melissa Martinez-Diaz's specialty?
- Melissa Martinez-Diaz is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Melissa Martinez-Diaz located?
- Melissa Martinez-Diaz's practice location on file with NPPES is 720 Pleasanton Rd, San Antonio, TX 78214-1343.
- What is Melissa Martinez-Diaz's phone number?
- The practice phone number listed in the NPPES registry for Melissa Martinez-Diaz is (210) 921-3800.
- Does Melissa Martinez-Diaz accept Medicare?
- Melissa Martinez-Diaz is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Melissa Martinez-Diaz's NPI active?
- Yes — Melissa Martinez-Diaz's NPI (1255350427) is active in the NPPES registry as of the last update on 2022-01-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.