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WEST SIDE MEDICAL GROUP, P.C.
NPI 1265553622
Internal Medicine in New York, NY

Active since April 03, 2007CLIA 33D0997595 · Waiver
314 W 14TH ST, NEW YORK, NY 10014(212) 438-6000(646) 638-1842 Get Directions Write a Review

NPPES record last updated: November 2, 2007. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About West Side Medical Group, P.c. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

WEST SIDE MEDICAL GROUP, P.C. (NPI 1265553622) is a healthcare organization registered as an internal medicine in New York, New York and active in the NPI registry since April 2007. The organization holds a CLIA Waiver certificate valid through March 20, 2028 and lists John Dellosso, Owner, as its authorized official.

NPPES Registry Identity

NPI1265553622
Entity TypeOrganization
Primary Taxonomy207R00000X
Legal Business NameWEST SIDE MEDICAL GROUP, P.C.
Location Address314 W 14TH STNew York, NY 10014-5002
Mailing Address314 W 14th StNew York, NY 10014-5002 · (212) 438-6000 · Fax (646) 638-1842
Phone(212) 438-6000
Fax(646) 638-1842
Organization SubpartNo
Authorized OfficialJohn DellossoOwner · (212) 638-4000
Enumeration DateApril 3, 2007
Last NPPES UpdateNovember 2, 2007
✔ NPI 1265553622 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
License✔ Licensed in NY · 103415
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
314 W 14TH ST, New York, NY 10014
Open in Google Maps ↗

Other Identifiers 1

Medicare PINWAA921NY

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

West Side Medical Group, P.c. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to West Side Medical Group, P.C., which bills Medicare for the services this clinician delivers.

Clinician (1)

John Dellosso, MD
Internal Medicine
NPI 1942299920
314 W 14TH ST 1ST FLOOR
New York, NY 10014
(646) 638-4000
✔ PECOS✔ Accepts MedicareSame address

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

CLIA Laboratory Certificates CMS CLIA

Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.

Certificate of Waiver 33D0997595

West Side Medical Group PC · New York, NY
Active · expires Mar 20, 2028
CLIA Number33D0997595
Laboratory TypePhysician Office
Certificate Effective DateMarch 21, 2026
Certificate Expiration DateMarch 20, 2028
Laboratory DirectorJohn V. Dellosso
Laboratory Phone(646) 638-4000
Laboratory LocationWest Side Medical Group PC314 West 14th St 1st Floor, New York, NY 10014
CLIA data matches this NPI record on: Address Name
This certificate is issued to a laboratory to perform only waived tests.

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 West Side Medical Group, P.C.'s NPI number?

The NPI number for West Side Medical Group, P.C. is 1265553622. It was assigned to this organization in the NPPES registry on April 3, 2007.

Where is West Side Medical Group, P.C. located?

West Side Medical Group, P.C. is located at 314 W 14th St, New York, NY 10014. The listed phone number is (212) 438-6000.

What is West Side Medical Group, P.C.'s specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is West Side Medical Group, P.C. enrolled in Medicare?

Yes. West Side Medical Group, P.C. is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through West Side Medical Group, P.C.?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Internal Medicine) reassigns their Medicare billing to West Side Medical Group, P.C.. A 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 the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does West Side Medical Group, P.C. hold a CLIA laboratory certificate?

Yes. A Certificate of Waiver (number 33D0997595) is associated with this NPI, valid through March 20, 2028. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

When was this NPI record last updated?

The NPPES record for West Side Medical Group, P.C. was last updated on November 2, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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.