Ian Armstrong, MD
Ian Armstrong, MD is a Neurological Surgery Physician in Fort Sam Houston, TX, registered under NPI 1851300859.
Getting there
The practice address on file is 3551 ROGER BROOKE DR, Fort Sam Houston, 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 |
|---|---|---|
| U0747 | TX | Neurological Surgery Physician primary |
| WA50707C | CA | Neurological Surgery Physician |
Licences are recorded in 2 states: TX, CA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
Licensed in 2 states
This provider holds licences in 2 states: California and Texas. The practice address on file is in Fort Sam Houston, 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
- U0747
- Specialty
- Neurological Surgery Physician
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 Neurological Surgery covers
A neurological surgeon provides the operative and non-operative management (i.e., prevention, diagnosis, evaluation, treatment, critical care, and rehabilitation) of disorders of the central, peripheral, and autonomic nervous systems, including their supporting structures and vascular supply; the evaluation and treatment of pathological processes which modify function or activity of the nervous system; and the operative and non-operative management of pain. A neurological surgeon treats patients with disorders of the nervous system; disorders of the brain, meninges, skull, and their blood supply, including the extracranial carotid and vertebral arteries; disorders of the pituitary gland; disorders of the spinal cord, meninges, and vertebral column, including those which may require treatment by spinal fusion or instrumentation; and disorders of the cranial and spinal nerves throughout their distribution. NUCC Health Care Provider Taxonomy, code 207T00000X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207T00000X | Neurological Surgery Physician | U0747 | TX | primary |
| 207T00000X | Neurological Surgery Physician | WA50707C | CA |
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 | 1851300859 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Aug 7, 2006 |
| Last updated | May 14, 2024 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
3551 ROGER BROOKE DR Fort Sam Houston, TX 78234 (210) 539-9092 |
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 | 8 | 5 | 1 | 3 | 0 | 0 | 8 | 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 1 | 1 | 6 | 0 | 0 | 8 | 1 |
Sum = 51 · next multiple of 10 = 60 · check digit = 9 · actual last digit = 9
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.