William Marrin, PHD
NPI 1861493629 · Psychologist · Port Jefferson, NY
Enrolled with Medicare as Practitioner - Clinical Psychologist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
William Marrin, PHD is a Psychologist provider in Port Jefferson, NY (NPI 1861493629).
Provider details
- NPI number
- 1861493629
- Entity type
- Individual
- Primary specialty
- PsychologistBehavioral Health & Social Service Providers
- Credential
- PHD
- Sex
- Male
- Sole proprietor
- Yes
- License
- 008777 (NY)
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
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
Mailing address
Registry dates
- Enumerated
- 2005-08-02
- Last updated
- 2011-05-05
Frequently asked questions
- What is William Marrin's NPI number?
- William Marrin's National Provider Identifier (NPI) is 1861493629, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is William Marrin's specialty?
- William Marrin is listed in the NPPES registry with a primary specialty of Psychologist (Behavioral Health & Social Service Providers).
- Where is William Marrin located?
- William Marrin's practice location on file with NPPES is 200 Belle Terre Rd, Port Jefferson, NY 11777-1928.
- What is William Marrin's phone number?
- The practice phone number listed in the NPPES registry for William Marrin is (631) 474-6000.
- Does William Marrin accept Medicare?
- William Marrin is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is William Marrin's NPI active?
- Yes — William Marrin's NPI (1861493629) is active in the NPPES registry as of the last update on 2011-05-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.