John Diehl, MS
NPI 1619187101 · Mental Health Counselor · West Sayville, NY
John Diehl, MS is a Mental Health Counselor provider in West Sayville, NY (NPI 1619187101).
Provider details
- NPI number
- 1619187101
- Entity type
- Individual
- Primary specialty
- Mental Health CounselorBehavioral Health & Social Service Providers
- Credential
- MS
- Sex
- Male
- Sole proprietor
- Yes
- License
- 001807-1 (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
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
- 2007-05-23
- Last updated
- 2007-07-08
Frequently asked questions
- What is John Diehl's NPI number?
- John Diehl's National Provider Identifier (NPI) is 1619187101, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Diehl's specialty?
- John Diehl is listed in the NPPES registry with a primary specialty of Mental Health Counselor (Behavioral Health & Social Service Providers).
- Where is John Diehl located?
- John Diehl's practice location on file with NPPES is 131 Cherry Ave, West Sayville, NY 11796-1214.
- What is John Diehl's phone number?
- The practice phone number listed in the NPPES registry for John Diehl is (631) 834-5809.
- Is John Diehl's NPI active?
- Yes — John Diehl's NPI (1619187101) 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.