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

Mrs. Gillian Brennan, PA

Individual provider Medical Physician Assistant · NPI 1639210750

Mrs. Gillian Brennan, PA is a Physician Assistant in Syosset, New York. Qualified in 2003, 23 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
23
Licensed in
NY
In the registry since
2007
What do these letters mean?
PA — Physician Assistant
A licensed clinician who examines, diagnoses and treats under a physician's supervision.

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Practice location Address checks out

221 Jericho Tpke
Syosset, NY 11791-4515 Not confirmed with CMS for 12 years — call before visiting
Phone: (516) 496-2752
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Medical Physician Assistant (primary) Taxonomy 363AM0700X · Licence 009844 (NY)

Record details

NPI number1639210750
Entity typeIndividual (Type 1)
GenderFemale
Credentials PA
Sole proprietorNo
NPI enumeratedFebruary 9, 2007
Last updated in NPPESJune 24, 2014

Medicare enrollment

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

Medicare specialtyPHYSICIAN ASSISTANT
Medical schoolOTHER
Graduated 2003 (23 years in practice)
Group practice North Shore-Lij Medical Pc — 6350 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations10 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients13
Services billed 14 a service is one billed item, such as a visit, a test or a procedure
Average patient age76

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at North Shore-Lij Medical PC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 6350 clinicians in the practice; 12 are shown here.

Other providers in Syosset