John Callahan, PH.D.
NPI 1346264421 · Clinical Psychologist · Hartford, CT
Enrolled with Medicare as Practitioner - Clinical Psychologist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Callahan, PH.D. is a Clinical Psychologist provider in Hartford, CT (NPI 1346264421).
Provider details
- NPI number
- 1346264421
- Entity type
- Individual
- Primary specialty
- Clinical PsychologistBehavioral Health & Social Service Providers
- Credential
- PH.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 001612 (CT)
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
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
- 2006-07-26
- Last updated
- 2007-07-08
Frequently asked questions
- What is John Callahan's NPI number?
- John Callahan's National Provider Identifier (NPI) is 1346264421, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Callahan's specialty?
- John Callahan is listed in the NPPES registry with a primary specialty of Clinical Psychologist (Behavioral Health & Social Service Providers).
- Where is John Callahan located?
- John Callahan's practice location on file with NPPES is 664 Prospect Ave, Hartford, CT 06105-4203.
- What is John Callahan's phone number?
- The practice phone number listed in the NPPES registry for John Callahan is (860) 236-8087.
- Does John Callahan accept Medicare?
- John Callahan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Callahan's NPI active?
- Yes — John Callahan's NPI (1346264421) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.