NPI age
19 years
Enumerated 2006-07-03
● Active
Type 1 · Individual
John Joseph Mahmarian, M.D.
Mahmarian is 1 of 422 internal medicine providers in Houston and 1 of 2301 in Texas.
Primary specialty
Internal Medicine
Licensed in
TX
1 state
Status
Active
No deactivations on record
Last NPPES update
2014-03-07
Source: monthly bulk 2026-05
Sole proprietor
No
May be part of a larger org
How this provider compares
Across 2301 active internal medicine providers in Texas.
NPI age
19 years
≈ at median (19 yr)
State licenses
1 state
11% of peers hold multiple states
Subspecialties
0
37% of peers hold subspecialties
NPI lifetime · 2006 → 2026
2006-07Enumerated in NPPES
2006
2026
Where they practice
Practice location
6550 Fannin St, Smith Tower, Suite 1901
Houston, TX 770302717
Mailing address
6550 Fannin St, Smith Tower, Suite 1901
Houston, TX 770302717
Specialties
-
Internal Medicine PrimaryAn internist who specializes in diseases of the heart and blood vessels and manages complex cardiac conditions such as heart attacks and life-threatening, abnormal heartbeat rhythms.
Identifiers
| Type | Value | Notes |
|---|---|---|
| 01 (TX) | 770000927 | MEDICARE 3 |
| 01 (TX) | 00T79S | MEDICARE1 |
| 05 (TX) | 134999510 | |
| 05 (TX) | 134999511 | |
| 01 (TX) | P00295327 | RAILROAD MEDICARE |
| 01 (TX) | P01036901 | RR MEDICARE |
| 01 (TX) | 612341 | MEDICARE 2 |
| 05 (TX) | 134999509 | |
| 05 (LA) | 1375250 | |
| 01 (TX) | 8U8373 | BLUE CROSS BLUE SHIELD |
Practice context
Part of a multi-provider practice. 376 other active providers share this practice address in NPPES.
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- Confirm the NPI on NPPES.The CMS registry is the system of record. Open NPPES →
- Check the state license is currently active.State licensing boards publish current status; NPPES does not.
- Confirm payer enrollment if billing.NPI presence does not guarantee active enrollment with Medicare, Medicaid, or commercial payers.