Brendan O'brien, M.D.
Brendan O'brien, M.D. is a Trauma Surgery Physician in San Antonio, TX, registered under NPI 1598073181. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 3551 ROGER BROOKE DR, San Antonio, TX 78234. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| T9464 | TX | Trauma Surgery Physician primary |
| 0101251259 | VA | Surgery Physician |
| ME146116 | FL | Surgical Critical Care Physician |
Licences are recorded in 3 states: TX, VA, FL. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Critical Care (intensivists)
- PAC ID
- 5092156588
Medicare enrolment is recorded as approved under the provider type Practitioner - Critical Care (intensivists). This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
Licensed in 3 states
This provider holds licences in 3 states: Florida, Texas and Virginia. The practice address on file is in San Antonio, TX, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Trauma Surgery covers
Trauma surgery is a recognized subspecialty of general surgery. Trauma surgeons are physicians who have completed a five-year general surgery residency and usually continue with a one to two year fellowship in trauma and/or surgical critical care, typically leading to additional board certification in surgical critical care. There is no trauma surgery board certification at this point. To obtain board certification in surgical critical care, a fellowship in surgical critical care or anesthesiology critical care must be completed during or after general surgery residency. NUCC Health Care Provider Taxonomy, code 2086S0127X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 2086S0127X | Trauma Surgery Physician Trauma Surgery | T9464 | TX | primary |
| 208600000X | Surgery Physician | 0101251259 | VA | |
| 2086S0102X | Surgical Critical Care Physician Surgical Critical Care | ME146116 | FL |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1598073181 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 17, 2010 |
| Last updated | Dec 8, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
3551 ROGER BROOKE DR San Antonio, TX 78234 (210) 539-9582 |
| Mailing address |
8901 WISCONSIN AVE Bethesda, MD 20889 |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 5 | 9 | 8 | 0 | 7 | 3 | 1 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 9 | 8 | 0 | 7 | 6 | 1 | 7 |
Sum = 69 · next multiple of 10 = 70 · check digit = 1 · actual last digit = 1
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.