Allyson Sy, MS, RD
NPI 1831794254 · Registered Dietitian · San Mateo, CA
Allyson Sy, MS, RD is a Registered Dietitian provider in San Mateo, CA (NPI 1831794254).
Provider details
- NPI number
- 1831794254
- Entity type
- Individual
- Primary specialty
- Registered DietitianDietary & Nutritional Service Providers
- Credential
- MS, RD
- Sex
- Female
- Sole proprietor
- Yes
- License
- 86044497 (CA)
Specialties & taxonomies
Dietary & Nutritional Service Providers
Dietary & Nutritional Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
5 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2020-12-02
- Last updated
- 2020-12-02
- Certified
- 2020-12-02
Frequently asked questions
- What is Allyson Sy's NPI number?
- Allyson Sy's National Provider Identifier (NPI) is 1831794254, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Allyson Sy's specialty?
- Allyson Sy is listed in the NPPES registry with a primary specialty of Registered Dietitian (Dietary & Nutritional Service Providers).
- Where is Allyson Sy located?
- Allyson Sy's practice location on file with NPPES is 2713 S Norfolk St Apt 311, San Mateo, CA 94403-1601.
- What is Allyson Sy's phone number?
- The practice phone number listed in the NPPES registry for Allyson Sy is (650) 243-7744.
- Is Allyson Sy's NPI active?
- Yes — Allyson Sy's NPI (1831794254) is active in the NPPES registry as of the last update on 2020-12-02.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.