Alyssa Poythress, RDN
Alyssa Poythress, RDN is a Registered Dietitian in Clarksville, TN, registered under NPI 1003621426. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
Here is what surrounds this office in Clarksville, based on OpenStreetMap data collected Oct 11, 2026. No dedicated parking is recorded within walking distance, so allow extra time to find street parking. The nearest transit stop is 652 ft away, served by Social Security Administration. If you arrive early, there is a coffee shop 0.36 mi away.
Getting here and what is nearby
Coffee Lasaters Coffee & Tea 200 ft ~1 min
Transit Center Pointe Drive 307 ft ~2 min
Transit Center Pointe Drive 380 ft ~2 min
Coffee Tropical Cafe 452 ft ~2 min
Restaurant Hot Worx 470 ft ~2 min
Restaurant Nothing Bundt Cakes 498 ft ~2 min
Transit Social Security Administration 652 ft ~3 min
Restaurant Zaxby's 0.35 mi ~7 min
2119 Lowes Drive, Clarksville
Mo-Th 11:00-20:30; Fr-Sa 11:00-21:30; Su 11:00-20:30
Coffee Starbucks 0.36 mi ~8 min
Gas station Kroger 0.43 mi ~9 min
Grocery Kroger 0.50 mi ~10 min
2100 Lowes Drive, Clarksville 37040
Mo-Su 06:00-22:00
Distances are straight‑line estimates — walking routes may be longer. Hours and phone numbers can change; call ahead to confirm.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 4453 | TN | Registered Dietitian primary |
This provider holds licence 4453 issued in TN. 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 Dietitian, Registered covers
A Registered Dietitian (RD)/Registered Dietitian Nutritionist (RDN) is an individual uniquely trained in the science of nutrition and practice of dietetics to design and provide medical nutrition therapy (MNT) and other evidence-based applications of the Nutrition Care Process (NCP) that exemplify the profession's systematic approach to providing high quality nutrition care. Registered dietitians provide MNT for the purpose of disease prevention or management, or to treat or rehabilitate an illness, injury, or condition, with the use of specific, indicated physical and cognitive nutrition care services comprised of one or more of the following aspects of the NCP: nutrition assessment/reassessment, nutrition diagnosis, nutrition intervention (e.g., nutrition counseling, therapeutic diet ordering, and nutrition education) and nutrition monitoring and evaluation. NUCC Health Care Provider Taxonomy, code 133V00000X
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 | 1003621426 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Feb 12, 2025 |
| Last updated | May 23, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | RDN |
| Practice address |
2250 WILMA RUDOLPH BLVD STE F Clarksville, TN 37040 (931) 257-6503 |
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 | 0 | 0 | 3 | 6 | 2 | 1 | 4 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 3 | 2 | 2 | 4 | 4 |
Sum = 44 · next multiple of 10 = 50 · check digit = 6 · actual last digit = 6
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.