Katherine Lilja
Katherine Lilja is an Obesity and Weight Management Nutrition Registered Dietitian in Fairfax, VA, registered under NPI 1477434611. 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 3580 JOSEPH SIEWICK DR STE 205, Fairfax, VA 22033. 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.
- Status
- Approved
- Provider type
- Practitioner - Registered Dietitian Or Nutrition Professional
- PAC ID
- 6608366620
- Enrollment ID
- I20251107002441
Medicare enrolment is recorded as approved under the provider type Practitioner - Registered Dietitian Or Nutrition Professional. 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 Nutrition, Obesity and Weight Management covers
An individual who is a Board Certified Specialist for Obesity and Weight Management and educates, supports, and advocates for patients and clients to understand and manage their weight and associated risks through the use of nutritional, behavioral health, medical, surgical, pharmacotherapeutic, and exercise and physical activity interventions. NUCC Health Care Provider Taxonomy, code 133VN1201X
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 | 1477434611 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Sep 11, 2025 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Practice address |
3580 JOSEPH SIEWICK DR STE 205 Fairfax, VA 22033 (703) 620-3211 |
| Mailing address |
4351 FARM HOUSE LN Fairfax, VA 22032 |
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 | 4 | 7 | 7 | 4 | 3 | 4 | 6 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 4 | 5 | 7 | 8 | 3 | 8 | 6 | 2 |
Sum = 69 · next multiple of 10 = 70 · check digit = 1 · actual last digit = 1
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.