1. Home
  2. Directory
  3. Virginia
  4. Alexandria
  5. Internal Medicine
  6. NPI Profile

ROBERT A. NUSSBAUM, MD, P.C.
NPI 1598041477
Internal Medicine - Gastroenterology in Alexandria, VA

Active since October 24, 2011CLIA 49D0968758 · Waiver
6355 WALKER LN, STE 309, ALEXANDRIA, VA 22310(703) 313-8400(703) 313-9666 Get Directions Write a Review

NPPES record last updated: March 4, 2014. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Robert A. Nussbaum, Md, P.c. NPPES

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

ROBERT A. NUSSBAUM, MD, P.C. (NPI 1598041477) is a healthcare organization registered as a gastroenterology in Alexandria, Virginia and active in the NPI registry since October 2011. The organization holds a CLIA Waiver certificate valid through December 20, 2027 and lists Robert A Nussbaum, President, as its authorized official.

NPPES Registry Identity

NPI1598041477
Entity TypeOrganization
Primary Taxonomy207RG0100X
Legal Business NameROBERT A. NUSSBAUM, MD, P.C.
Location Address6355 WALKER LN, STE 309Alexandria, VA 22310-3247
Mailing Address6355 Walker Ln, Ste 309Alexandria, VA 22310-3247 · (703) 313-8400 · Fax (703) 313-9666
Phone(703) 313-8400
Fax(703) 313-9666
Organization SubpartNo
Authorized OfficialRobert A NussbaumPresident · (703) 313-8400
Enumeration DateOctober 24, 2011
Last NPPES UpdateMarch 4, 2014
✔ NPI 1598041477 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · GastroenterologyAllopathic & Osteopathic Physicians
Taxonomy Code207RG0100X
License✔ Licensed in VA · 0101047887
Definition
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs.
6355 WALKER LN, Alexandria, VA 22310
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

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Robert A. Nussbaum, Md, 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 Robert A. Nussbaum, MD, P.C., which bills Medicare for the services this clinician delivers.

Clinician (1)

Robert Nussbaum, M.D.
Gastroenterology
NPI 1659364511
6355 WALKER LN SUITE # 309
Alexandria, VA 22310
(703) 313-8400
✔ 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 49D0968758

Robert A Nussbaum MD PC · Alexandria, VA
Active · expires Dec 20, 2027
CLIA Number49D0968758
Laboratory TypePhysician Office
Certificate Effective DateDecember 21, 2025
Certificate Expiration DateDecember 20, 2027
Laboratory DirectorRobert A. Nussbaum MD
Laboratory Phone(703) 313-8400
Laboratory LocationRobert A Nussbaum MD PC6355 Walker Lane - Suite 309, Alexandria, VA 22310
CLIA data matches this NPI record on: Address Name Phone
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 Robert A. Nussbaum, MD, P.C.'s NPI number?

The NPI number for Robert A. Nussbaum, MD, P.C. is 1598041477. It was assigned to this organization in the NPPES registry on October 24, 2011.

Where is Robert A. Nussbaum, MD, P.C. located?

Robert A. Nussbaum, MD, P.C. is located at 6355 Walker Ln Ste 309, Alexandria, VA 22310. The listed phone number is (703) 313-8400.

What is Robert A. Nussbaum, MD, P.C.'s specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.

Is Robert A. Nussbaum, MD, P.C. enrolled in Medicare?

Yes. Robert A. Nussbaum, MD, P.C. is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Robert A. Nussbaum, MD, P.C.?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Gastroenterology) reassigns their Medicare billing to Robert A. Nussbaum, MD, 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 Robert A. Nussbaum, MD, P.C. hold a CLIA laboratory certificate?

Yes. A Certificate of Waiver (number 49D0968758) is associated with this NPI, valid through December 20, 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 Robert A. Nussbaum, MD, P.C. was last updated on March 4, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 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.