DR. GREGORY J. GUNYAN D.O.
NPI 1528386265
Psychiatry & Neurology - Psychiatry in Smithtown, NY
About Dr. Gregory J. Gunyan D.o. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. GREGORY J. GUNYAN D.O. (NPI 1528386265) is an individual psychiatry provider in Smithtown, New York, licensed in New York (267344) and active in the NPI registry since May 2010. He is enrolled in Medicare PECOS, is affiliated with Mount Sinai South Nassau, and is a graduate of New York College Of Osteo Medicine Of New York Institute Of Technology (2009).
NPPES Registry Identity
Specialties & Licenses 2
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Dr. Gregory J. Gunyan D.o. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
2Medicare enrollment records show Gregory Gunyan reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Oceanside, NY 11572
- Reassigned Medicare billing, New York enrollment
- 22 clinicians in this Medicare group
Boynton Beach, FL 33426
- Reassigned Medicare billing, New York enrollment
- 7,712 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Areas of Expertise CMS Part B claims 3
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mount Sinai South Nassau
Acute Care Hospitals · Oceanside, NYPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 11787 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Gregory Gunyan's NPI number?
The NPI number for Gregory Gunyan is 1528386265. It was assigned to this individual provider in the NPPES registry on May 5, 2010.
Where is Gregory Gunyan located?
Gregory Gunyan practices at 222 E Middle Country Rd Ste 111, Smithtown, NY 11787. The listed phone number is (631) 265-1622.
What is Gregory Gunyan's specialty?
The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.
Is Gregory Gunyan enrolled in Medicare?
Yes. Gregory Gunyan is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Gregory Gunyan's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Gregory Gunyan reassigns Medicare benefits to 2 organizations: South Nassau Communities Hospital (Oceanside, NY) and New York University (Boynton Beach, FL). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Gregory Gunyan's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Gregory Gunyan accept?
Health plans from Cigna HealthCare of Florida, Inc., Cigna Healthcare and UnitedHealthcare list Gregory Gunyan as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Gregory Gunyan affiliated with any hospitals?
According to CMS data, Gregory Gunyan is affiliated with Mount Sinai South Nassau.
When was this NPI record last updated?
The NPPES record for Gregory Gunyan was last updated on November 14, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Dr. Gregory J. Gunyan, D.O. · NPI 1528386265
Psychiatry physician in Smithtown, New York. Individual provider, active in the CMS NPPES registry since May 5, 2010.
## Identity
- **NPI:** 1528386265 (Entity type: Individual)
- **Enumerated:** May 5, 2010
- **Primary specialty:** Psychiatry & Neurology - Psychiatry · taxonomy 2084P0800X
- **State license:** 267344 (New York)
- **Sole proprietor:** No
## Practice location
- **Address:** 222 E MIDDLE COUNTRY RD STE 111, Smithtown, NY 11787-2873
- **Phone:** (631) 265-1622
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): South Nassau Communities Hospital (NPI 1073594800, Oceanside, NY); New York University (NPI 1285826438, Boynton Beach, FL) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** New York College Of Osteo Medicine Of New York Institute Of Technology, class of 2009
## Record status
- **NPPES last updated:** November 14, 2014
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Source: [NPI Profile](https://npiprofile.com/npi/1528386265) · Data from the CMS NPPES public registry.