John Mazellan, LCSW
NPI 1851577472 · Clinical Social Worker · Hillsborough, NJ
John Mazellan, LCSW is a Clinical Social Worker provider in Hillsborough, NJ (NPI 1851577472).
Provider details
- NPI number
- 1851577472
- Entity type
- Individual
- Primary specialty
- Clinical Social WorkerBehavioral Health & Social Service Providers
- Credential
- LCSW
- Sex
- Male
- Sole proprietor
- Yes
- License
- 44SC00606600 (NJ)
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
- 2008-01-14
- Last updated
- 2008-01-14
Frequently asked questions
- What is John Mazellan's NPI number?
- John Mazellan's National Provider Identifier (NPI) is 1851577472, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Mazellan's specialty?
- John Mazellan is listed in the NPPES registry with a primary specialty of Clinical Social Worker (Behavioral Health & Social Service Providers).
- Where is John Mazellan located?
- John Mazellan's practice location on file with NPPES is 390 Amwell Rd, Hillsborough, NJ 08844-1225.
- What is John Mazellan's phone number?
- The practice phone number listed in the NPPES registry for John Mazellan is (908) 431-9200.
- Is John Mazellan's NPI active?
- Yes — John Mazellan's NPI (1851577472) is active in the NPPES registry as of the last update on 2008-01-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.