Cynthia Armstrong, NP
Cynthia Armstrong, NP is a Family Nurse Practitioner in Sherman, TX, registered under NPI 1841634722.
Getting there
The practice address on file is 315 W MCLAIN DR, Sherman, TX 75092. 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 |
|---|---|---|
| AP123487 | TX | Family Nurse Practitioner primary |
This provider holds licence AP123487 issued in TX. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Nurse Practitioner
- PAC ID
- 7416196720
- Enrollment ID
- I20130618000409
Medicare enrolment is recorded as approved under the provider type Practitioner - Nurse Practitioner. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Family covers
Definition to come... NUCC Health Care Provider Taxonomy, code 363LF0000X
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 | 1841634722 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 23, 2013 |
| Last updated | Mar 19, 2026 |
| Status | Active |
| Sole proprietor | No |
| Credential | NP |
| Practice address |
315 W MCLAIN DR Sherman, TX 75092 (903) 957-4701 Fax (903) 957-3416 |
| Other identifiers |
323122705
· Medicaid (TX) |
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 | 4 | 1 | 6 | 3 | 4 | 7 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 8 | 1 | 3 | 3 | 8 | 7 | 4 |
Sum = 68 · next multiple of 10 = 70 · check digit = 2 · actual last digit = 2
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.