1. Home
  2. Directory
  3. Connecticut
  4. Old Greenwich
  5. Internal Medicine
  6. NPI Profile

OLD GREENWICH MEDICAL GROUP LLC
NPI 1730932880
Internal Medicine in Old Greenwich, CT

Active since April 09, 2024CLIA 07D2037604 · Waiver
8 W END AVE, OLD GREENWICH, CT 06870(203) 637-5400(203) 637-5408 Get Directions Write a Review

NPPES record last updated: May 7, 2024. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: May 7, 2024, Apr 9, 2024 (2 updates tracked since 2024).

About Old Greenwich Medical Group Llc NPPES

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

OLD GREENWICH MEDICAL GROUP LLC (NPI 1730932880) is a healthcare organization registered as an internal medicine in Old Greenwich, Connecticut and active in the NPI registry since April 2024. The organization holds a CLIA Waiver certificate valid through March 1, 2028 and lists Karyna Estrella, Pracice Manager, as its authorized official.

NPPES Registry Identity

NPI1730932880
Entity TypeOrganization
Primary Taxonomy207R00000X
Legal Business NameOLD GREENWICH MEDICAL GROUP LLC
Location Address8 W END AVEOld Greenwich, CT 06870-1642
Mailing Address8 W End AveOld Greenwich, CT 06870-1642 · (203) 637-5400 · Fax (203) 637-5408
Phone(203) 637-5400
Fax(203) 637-5408
Organization SubpartNo
Authorized OfficialKaryna EstrellaPracice Manager · (203) 637-5400
Enumeration DateApril 9, 2024
Last NPPES UpdateMay 7, 20242 updates tracked since enumeration
NPPES CertifiedMay 7, 2024
✔ NPI 1730932880 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
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.
8 W END AVE, Old Greenwich, CT 06870
Open in Google Maps ↗

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

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield.Insurance ›

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Old Greenwich Medical Group Llc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

5

Medicare enrollment records show 5 clinicians reassign Medicare billing to Old Greenwich Medical Group LLC, which bills Medicare for the services they deliver. Of these, 2 practice at this address and 4 within 10 miles. They are listed nearest first.

Clinicians, nearest first (5)

Rebecca Warkol, MD
Internal Medicine
NPI 1184820110
8 W END AVE
Old Greenwich, CT 06870
(203) 637-5406
✔ PECOS✔ Accepts MedicareSame address
Melanie Kelton, M.D.
Internal Medicine
NPI 1083918577
8 W END AVE
Old Greenwich, CT 06870
(203) 637-5400
✔ PECOS✔ Accepts MedicareSame address
Burton Rubin, M.D.
Internal Medicine
NPI 1134105414
8 W END AVE
Old Greenwich, CT 06870
(203) 637-5406
✔ PECOS✔ Accepts Medicare0.1 mi
Caroline Lodato, MD
Internal Medicine
NPI 1609075324
5 PERRYRIDGE RD GREENWICH HOSPITAL
Greenwich, CT 06830
(203) 863-3840
✔ PECOS✔ Accepts Medicare3.1 mi
Tao Du, M.D.
Internal Medicine
NPI 1376704916
13625 MAPLE AVE STE 210
Flushing, NY 11355
(203) 391-4853
✔ PECOS✔ Accepts Medicare23 mi

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 07D2037604

Old Greenwich Medical Group · Old Greenwich, CT
Active · expires Mar 1, 2028
CLIA Number07D2037604
Laboratory TypePhysician Office
Certificate Effective DateMarch 2, 2026
Certificate Expiration DateMarch 1, 2028
Laboratory DirectorJayne Pincus
Laboratory Phone(203) 637-5406
Laboratory LocationOld Greenwich Medical Group8 West End Avenue, Old Greenwich, CT 06870
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 Old Greenwich Medical Group LLC's NPI number?

The NPI number for Old Greenwich Medical Group LLC is 1730932880. It was assigned to this organization in the NPPES registry on April 9, 2024.

Where is Old Greenwich Medical Group LLC located?

Old Greenwich Medical Group LLC is located at 8 W End Ave, Old Greenwich, CT 06870. The listed phone number is (203) 637-5400.

What is Old Greenwich Medical Group LLC's specialty?

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

Is Old Greenwich Medical Group LLC enrolled in Medicare?

Yes. Old Greenwich Medical Group LLC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Old Greenwich Medical Group LLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 5 clinicians, all in Internal Medicine, reassign their Medicare billing to Old Greenwich Medical Group LLC. 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. Of these, 2 practice at this address and 4 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does Old Greenwich Medical Group LLC hold a CLIA laboratory certificate?

Yes. A Certificate of Waiver (number 07D2037604) is associated with this NPI, valid through March 1, 2028. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

What insurance does Old Greenwich Medical Group LLC accept?

Health plans from Anthem Blue Cross and Blue Shield list Old Greenwich Medical Group LLC 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.

When was this NPI record last updated?

The NPPES record for Old Greenwich Medical Group LLC was last updated on May 7, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.