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

MS. Diane Grassi, NP

Individual provider Gerontology Nurse Practitioner · NPI 1063917136

MS. Diane Grassi, NP is a Nurse Practitioner in Smithtown, New York. Graduated from State University of New York at Stony Brook, School of Medicine in 2016, 10 years ago. Practices with North Shore-Lij Medical PC, a 6,350-clinician group and accepts Medicare assignment. Licensed in New York.

Years since qualifying
10
Trained at
State University of New York at Stony Brook, School of Medicine
Licensed in
NY
In the registry since
2018
Specialties on file
2
What do these letters mean?
NP — Nurse Practitioner
An advanced practice nurse who can diagnose, treat and in most states prescribe.

See every abbreviation used in this directory →

Practice location Address checks out

285 E Main St
Smithtown, NY 11787-2978
Phone: (631) 656-0874
Show map & directions

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

Specialties & licences

Adult Health Nurse Practitioner (primary) Taxonomy 363LA2200X · Licence F308295-1 (NY)
Gerontology Nurse Practitioner Taxonomy 363LG0600X · Licence F308295-1 (NY)

Record details

NPI number1063917136
Entity typeIndividual (Type 1)
GenderFemale
Credentials NP
Sole proprietorYes
NPI enumeratedMarch 29, 2018
Last updated in NPPESJanuary 7, 2019
Mailing address7 Wendy Ln, Massapequa Park, NY 11762-3733

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyNURSE PRACTITIONER
Medical schoolSTATE UNIVERSITY OF NEW YORK AT STONY BROOK, SCHOOL OF MEDICINE
Graduated 2016 (10 years in practice)
Group practice North Shore-Lij Medical Pc — 6350 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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