Stephen Knowlton, PHD
NPI 1336291004 · Clinical Psychologist · Boston, MA
Stephen Knowlton, PHD is a Clinical Psychologist provider in Boston, MA (NPI 1336291004).
Provider details
- NPI number
- 1336291004
- Entity type
- Individual
- Primary specialty
- Clinical PsychologistBehavioral Health & Social Service Providers
- Credential
- PHD
- Sex
- Male
- Sole proprietor
- Yes
- License
- 6510 (MA)
Specialties & taxonomies
Behavioral Health & Social Service Providers
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
19 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
- 2007-01-16
- Last updated
- 2025-09-11
Frequently asked questions
- What is Stephen Knowlton's NPI number?
- Stephen Knowlton's National Provider Identifier (NPI) is 1336291004, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Stephen Knowlton's specialty?
- Stephen Knowlton is listed in the NPPES registry with a primary specialty of Clinical Psychologist (Behavioral Health & Social Service Providers).
- Where is Stephen Knowlton located?
- Stephen Knowlton's practice location on file with NPPES is 466 Commonwealth Ave, Boston, MA 02215-2721.
- What is Stephen Knowlton's phone number?
- The practice phone number listed in the NPPES registry for Stephen Knowlton is (617) 859-5806.
- Is Stephen Knowlton's NPI active?
- Yes — Stephen Knowlton's NPI (1336291004) is active in the NPPES registry as of the last update on 2025-09-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.