John Mahmarian, M.D.
NPI 1114957511 · Cardiovascular Disease Physician · Houston, TX
Enrolled with Medicare as Practitioner - Cardiovascular Disease (cardiology) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Mahmarian, M.D. is a Cardiovascular Disease Physician provider in Houston, TX (NPI 1114957511).
Provider details
- NPI number
- 1114957511
- Entity type
- Individual
- Primary specialty
- Cardiovascular Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- F9767 (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
1,905 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) |
|---|---|---|
| Ct Scan of Blood Vessels of Chest With Contrast71275 | 325 | $81 |
| Ct Scan of Blood Vessels and Grafts of Heart With Contrast75574 | 320 | $111 |
| Exercise Or Drug-Induced Heart Stress Test With Electrocardiogram (ecg) With Review By Physician93018 | 234 | $14 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 182 | $129 |
| Nuclear Medicine Studies of Blood Flow in Heart Muscle at Rest and With Stress With Concurrent Ct Scan78431 | 135 | $85 |
| Nuclear Medicine Study of Heart Muscle Blood Flow By Pet78434 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 33 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Rosuvastatin Calcium | 505 | 142 |
| Ezetimibe | 285 | 88 |
| Carvedilol | 249 | 66 |
| Losartan Potassium | 214 | 63 |
| Amlodipine Besylate | 152 | 49 |
| Atorvastatin Calcium | 133 | 38 |
| Hydrochlorothiazide | 125 | 39 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$92 across 4 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
- 2006-07-03
- Last updated
- 2014-03-07
Frequently asked questions
- What is John Mahmarian's NPI number?
- John Mahmarian's National Provider Identifier (NPI) is 1114957511, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Mahmarian's specialty?
- John Mahmarian is listed in the NPPES registry with a primary specialty of Cardiovascular Disease Physician (Allopathic & Osteopathic Physicians).
- Where is John Mahmarian located?
- John Mahmarian's practice location on file with NPPES is 6550 Fannin St, Houston, TX 77030-2717.
- What is John Mahmarian's phone number?
- The practice phone number listed in the NPPES registry for John Mahmarian is (713) 441-1100.
- Does John Mahmarian accept Medicare?
- John Mahmarian is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Mahmarian's NPI active?
- Yes — John Mahmarian's NPI (1114957511) is active in the NPPES registry as of the last update on 2014-03-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.