C Johnston
C Johnston is a Neurology Physician in Helotes, TX, registered under NPI 1700080330.
Getting there
The practice address on file is 11844 BANDERA RD NO. 705, Helotes, TX 78023. 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 |
|---|---|---|
| G8880 | TX | Neurology Physician primary |
This provider holds licence G8880 issued in TX. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
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.
What Neurology covers
A Neurologist specializes in the diagnosis and treatment of diseases or impaired function of the brain, spinal cord, peripheral nerves, muscles, autonomic nervous system, and blood vessels that relate to these structures. NUCC Health Care Provider Taxonomy, code 2084N0400X
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 | 1700080330 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 14, 2007 |
| Last updated | Jul 11, 2007 |
| Status | Active |
| Sole proprietor | No |
| Practice address |
11844 BANDERA RD NO. 705 Helotes, TX 78023 (210) 695-2766 |
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 | 7 | 0 | 0 | 0 | 8 | 0 | 3 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 7 | 0 | 0 | 0 | 8 | 0 | 3 | 6 |
Sum = 50 · next multiple of 10 = 50 · check digit = 0 · actual last digit = 0
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.