Diane Grassi, NP
NPI 1063917136 · Adult Health Nurse Practitioner · Smithtown, NY
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Diane Grassi, NP is a Adult Health Nurse Practitioner provider in Smithtown, NY (NPI 1063917136).
Provider details
- NPI number
- 1063917136
- Entity type
- Individual
- Primary specialty
- Adult Health Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- NP
- Sex
- Female
- Sole proprietor
- Yes
- License
- F308295-1 (NY)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
8 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
339 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. 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 .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 339 | $75 |
Typical Medicare-allowed amounts for these services range $75–$75 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$64 across 3 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2018-03-29
- Last updated
- 2019-01-07
Frequently asked questions
- What is Diane Grassi's NPI number?
- Diane Grassi's National Provider Identifier (NPI) is 1063917136, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Diane Grassi's specialty?
- Diane Grassi is listed in the NPPES registry with a primary specialty of Adult Health Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Diane Grassi located?
- Diane Grassi's practice location on file with NPPES is 285 E Main St, Smithtown, NY 11787-2978.
- What is Diane Grassi's phone number?
- The practice phone number listed in the NPPES registry for Diane Grassi is (631) 656-0874.
- Does Diane Grassi accept Medicare?
- Diane Grassi is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Diane Grassi's NPI active?
- Yes — Diane Grassi's NPI (1063917136) is active in the NPPES registry as of the last update on 2019-01-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.