Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Mr. John Diehl, MS

Individual provider Mental Health Counselor · NPI 1619187101

Mr. John Diehl, MS is a Mental Health Counselor in West Sayville, New York. Practices as a sole proprietor. Licensed in New York.

Licensed in
NY
In the registry since
2007
What do these letters mean?
MS — Master of Science
A graduate science degree.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

131 Cherry Ave
West Sayville, NY 11796-1214
Phone: (631) 834-5809
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Mental Health Counselor (primary) Taxonomy 101YM0800X · Licence 001807-1 (NY)

Record details

NPI number1619187101
Entity typeIndividual (Type 1)
GenderMale
Credentials MS
Sole proprietorYes
NPI enumeratedMay 23, 2007
Last updated in NPPESJuly 8, 2007

Other providers in West Sayville