Christina Ernst, MS,RD,CDN
Christina Ernst, MS,RD,CDN is a Registered Dietitian in Derby, CT, registered under NPI 1003070020. 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 Derby, based on OpenStreetMap data collected Sep 3, 2026. Parking is available about 255 ft away. The nearest transit stop is 808 ft away, served by Spring Street & Maple Avenue (Stop # 6148). A pharmacy sits 475 ft from the entrance (Griffin Pharmacy & Gifts), which helps if you leave with a prescription.
Getting here and what is nearby
Parking 36 ft ~1 min
Parking 212 ft ~1 min
Parking 255 ft ~1 min
Pharmacy Griffin Pharmacy & Gifts 475 ft ~2 min
Transit Spring Street & Maple Avenue (Stop # 6148) 808 ft ~4 min
Gas station Cumberland Farms 0.40 mi ~8 min
Restaurant Wingstop 0.44 mi ~9 min
49 Pershing Drive, Derby 06418
Grocery ShopRite 0.48 mi ~10 min
49 Pershing Drive, Derby 06418
Grocery Stop & Shop 0.50 mi ~11 min
100 Division Street, Ansonia 06401
Mo-Sa 07:00-23:00; Su 07:00-22:00
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 |
|---|---|---|
| 000833 | CT | Registered Dietitian primary |
This provider holds licence 000833 issued in CT. 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 | 1003070020 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 18, 2008 |
| Last updated | Jul 18, 2008 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Female |
| Credential | MS,RD,CDN |
| Practice address |
130 DIVISION ST Derby, CT 06418 (203) 732-7579 |
| Mailing address |
57 HIGHLAND AVE Watertown, CT 06795 |
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 | 0 | 7 | 0 | 0 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 0 | 7 | 0 | 0 | 4 |
Sum = 40 · next multiple of 10 = 40 · 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.