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MENDHAM MEDICAL PRACTICE LLC
NPI 1265917926
Internal Medicine in Mendham, NJ

Active since September 28, 2018CLIA 31D0116602 · Microscopy
19 E MAIN ST STE 1, MENDHAM, NJ 07945(973) 543-6505(973) 543-2967 Get Directions Write a Review

NPPES record last updated: November 14, 2018. Verified against the NPPES registry weekly; last sync: November 08, 2026.

Record update history: Nov 14, 2018, Sep 28, 2018 (2 updates tracked since 2018).

About Mendham Medical Practice Llc NPPES

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

MENDHAM MEDICAL PRACTICE LLC (NPI 1265917926) is a healthcare organization registered as an internal medicine in Mendham, New Jersey and active in the NPI registry since September 2018. The organization holds a CLIA Microscopy certificate valid through August 17, 2027 and lists Gregg G Marella, Sole Member, as its authorized official.

NPPES Registry Identity

NPI1265917926
Entity TypeOrganization
Primary Taxonomy207R00000X
Legal Business NameMENDHAM MEDICAL PRACTICE LLC
Location Address19 E MAIN ST STE 1Mendham, NJ 07945-1503
Mailing Address19 E Main St Ste 1Mendham, NJ 07945-1503 · (973) 543-6505 · Fax (973) 543-2967
Phone(973) 543-6505
Fax(973) 543-2967
Organization SubpartNo
Authorized OfficialGregg G MarellaSole Member · (973) 543-6505
Enumeration DateSeptember 28, 2018
Last NPPES UpdateNovember 14, 20182 updates tracked since enumeration
✔ NPI 1265917926 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.
19 E MAIN ST STE 1, Mendham, NJ 07945
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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)

Mendham Medical Practice Llc 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 Mendham Medical Practice LLC, which bills Medicare for the services this clinician delivers.

Clinician (1)

Gregg Marella, M.D.
Internal Medicine
NPI 1922116326
19 E MAIN ST
Mendham, NJ 07945
(973) 543-6505
✔ PECOSSame 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 for Provider-Performed Microscopy Procedures (PPMP) 31D0116602

Mendham Medical Practice, LLC · Mendham, NJ
Active · expires Aug 17, 2027
CLIA Number31D0116602
Laboratory TypePhysician Office
Certificate Effective DateAugust 18, 2025
Certificate Expiration DateAugust 17, 2027
Laboratory DirectorGregg G. Marella
Laboratory Phone(973) 543-6505
Laboratory LocationMendham Medical Practice, LLC19 E Main Street, Mendham, NJ 07945
CLIA data matches this NPI record on: Address Name Phone
This certificate is issued to a laboratory in which a physician, midlevel practitioner or dentist performs no tests other than the microscopy procedures. This certificate permits the laboratory to also perform 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 Mendham Medical Practice LLC's NPI number?

The NPI number for Mendham Medical Practice LLC is 1265917926. It was assigned to this organization in the NPPES registry on September 28, 2018.

Where is Mendham Medical Practice LLC located?

Mendham Medical Practice LLC is located at 19 E Main St Ste 1, Mendham, NJ 07945. The listed phone number is (973) 543-6505.

What is Mendham Medical Practice LLC's specialty?

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

Is Mendham Medical Practice LLC enrolled in Medicare?

Yes. Mendham Medical Practice LLC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Mendham Medical Practice LLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Internal Medicine) reassigns their Medicare billing to Mendham Medical Practice 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. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does Mendham Medical Practice LLC hold a CLIA laboratory certificate?

Yes. A Certificate for Provider-Performed Microscopy Procedures (PPMP) (number 31D0116602) is associated with this NPI, valid through August 17, 2027. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

When was this NPI record last updated?

The NPPES record for Mendham Medical Practice LLC was last updated on November 14, 2018. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 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.