Marcia Dadds, MS, RDN
Marcia Dadds, MS, RDN is a Registered Dietitian in Williamsburg, VA, registered under NPI 1891120994. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 501 PRINCE GEORGE ST SUITE 308, Williamsburg, VA 23185. 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
NPPES does not list a state licence number for this record. That is not unusual — organizations and some provider types are not required to file one. Verify current licensure with the relevant state board before care.
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
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 | |
|---|---|---|---|---|
| 133V00000X | Registered Dietitian | — | — | primary |
| 133N00000X | Nutritionist | — | — |
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 | 1891120994 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 8, 2013 |
| Last updated | Apr 18, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MS, RDN |
| Practice address |
501 PRINCE GEORGE ST SUITE 308 Williamsburg, VA 23185 (757) 603-3557 |
| Mailing address |
104 TAMPA CIR Williamsburg, VA 23188 |
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 | 9 | 1 | 1 | 2 | 0 | 9 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 9 | 1 | 2 | 2 | 0 | 9 | 9 |
Sum = 66 · next multiple of 10 = 70 · check digit = 4 · actual last digit = 4
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.