IndividualActive
Mary Williamson, PHD
NPI 1821041021 · Clinical Psychologist · Columbia, MO
Mary Williamson, PHD is a Clinical Psychologist provider in Columbia, MO (NPI 1821041021).
Provider details
- NPI number
- 1821041021
- Entity type
- Individual
- Primary specialty
- Clinical PsychologistBehavioral Health & Social Service Providers
- Credential
- PHD
- Sex
- Female
- Sole proprietor
- No
- License
- PY01775 (MO)
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
Detailed profile(91/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 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
3217 S Providence Rd
Columbia, MO 65203-3639
Phone: (573) 884-7733
Fax: (573) 884-5559
Street-level locationGet directions
Mailing address
Po Box 7687
Columbia, MO 65205-7687
Registry dates
- Enumerated
- 2006-05-18
- Last updated
- 2008-09-25
Frequently asked questions
- What is Mary Williamson's NPI number?
- Mary Williamson's National Provider Identifier (NPI) is 1821041021, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Williamson's specialty?
- Mary Williamson is listed in the NPPES registry with a primary specialty of Clinical Psychologist (Behavioral Health & Social Service Providers).
- Where is Mary Williamson located?
- Mary Williamson's practice location on file with NPPES is 3217 S Providence Rd, Columbia, MO 65203-3639.
- What is Mary Williamson's phone number?
- The practice phone number listed in the NPPES registry for Mary Williamson is (573) 884-7733.
- Is Mary Williamson's NPI active?
- Yes — Mary Williamson's NPI (1821041021) is active in the NPPES registry as of the last update on 2008-09-25.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.