Andrew Williamson, M.A.
NPI 1437320561 · Marriage & Family Therapist · Vallejo, CA
Andrew Williamson, M.A. is a Marriage & Family Therapist provider in Vallejo, CA (NPI 1437320561).
Provider details
- NPI number
- 1437320561
- Entity type
- Individual
- Primary specialty
- Marriage & Family TherapistBehavioral Health & Social Service Providers
- Credential
- M.A.
- Sex
- Male
- Sole proprietor
- No
- License
- 45589 (CA)
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
18 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
- 2008-03-17
- Last updated
- 2008-04-16
Frequently asked questions
- What is Andrew Williamson's NPI number?
- Andrew Williamson's National Provider Identifier (NPI) is 1437320561, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Andrew Williamson's specialty?
- Andrew Williamson is listed in the NPPES registry with a primary specialty of Marriage & Family Therapist (Behavioral Health & Social Service Providers).
- Where is Andrew Williamson located?
- Andrew Williamson's practice location on file with NPPES is 250 Georgia St, Vallejo, CA 94590-5930.
- What is Andrew Williamson's phone number?
- The practice phone number listed in the NPPES registry for Andrew Williamson is (707) 553-5328.
- Is Andrew Williamson's NPI active?
- Yes — Andrew Williamson's NPI (1437320561) is active in the NPPES registry as of the last update on 2008-04-16.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.