Gillian Brennan, PA
NPI 1639210750 · Medical Physician Assistant · Syosset, NY
Enrolled with Medicare as Practitioner - Physician Assistant · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gillian Brennan, PA is a Medical Physician Assistant provider in Syosset, NY (NPI 1639210750).
Provider details
- NPI number
- 1639210750
- Entity type
- Individual
- Primary specialty
- Medical Physician AssistantPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- PA
- Sex
- Female
- Sole proprietor
- No
- License
- 009844 (NY)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
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 methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-02-09
- Last updated
- 2014-06-24
Frequently asked questions
- What is Gillian Brennan's NPI number?
- Gillian Brennan's National Provider Identifier (NPI) is 1639210750, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gillian Brennan's specialty?
- Gillian Brennan is listed in the NPPES registry with a primary specialty of Medical Physician Assistant (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Gillian Brennan located?
- Gillian Brennan's practice location on file with NPPES is 221 Jericho Tpke, Syosset, NY 11791-4515.
- What is Gillian Brennan's phone number?
- The practice phone number listed in the NPPES registry for Gillian Brennan is (516) 496-2752.
- Does Gillian Brennan accept Medicare?
- Gillian Brennan is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gillian Brennan's NPI active?
- Yes — Gillian Brennan's NPI (1639210750) is active in the NPPES registry as of the last update on 2014-06-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.