1. Home
  2. Directory
  3. California
  4. Napa
  5. Obstetrics Gynecology
  6. NPI Profile

JOHN T ARMSTRONG JR MD INC
NPI 1598830564
Obstetrics & Gynecology - Gynecology in Napa, CA

Active since November 22, 2006CLIA 05D0709799 · Microscopy
3434 VILLA LN STE 360, NAPA, CA 94558(707) 257-4317 Get Directions Write a Review

NPPES record last updated: August 28, 2014. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About John T Armstrong Jr Md Inc NPPES

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

JOHN T ARMSTRONG JR MD INC (NPI 1598830564) is a healthcare organization registered as a gynecology in Napa, California and active in the NPI registry since November 2006. The organization holds a CLIA Microscopy certificate valid through November 1, 2027 and lists John Armstrong, President, as its authorized official.

NPPES Registry Identity

NPI1598830564
Entity TypeOrganization
Primary Taxonomy207VG0400X
Legal Business NameJOHN T ARMSTRONG JR MD INC
Location Address3434 VILLA LN STE 360Napa, CA 94558-6416
Mailing Address3010 Beard RdNapa, CA 94558-3442 · (707) 255-8825
Phone(707) 257-4317
Organization SubpartNo
Authorized OfficialJohn ArmstrongPresident · (707) 255-8825
Enumeration DateNovember 22, 2006
Last NPPES UpdateAugust 28, 2014
✔ NPI 1598830564 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyObstetrics & Gynecology · GynecologyAllopathic & Osteopathic Physicians
Taxonomy Code207VG0400X
License✔ Licensed in CA · C37899
Definition
A physician who specializes in diagnosis, treatment, and management of patients with gynecologic conditions. Source: National Uniform Claim Committee
3434 VILLA LN STE 360, Napa, CA 94558
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)

John T Armstrong Jr Md Inc 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 John T Armstrong Jr MD Inc, which bills Medicare for the services this clinician delivers.

Clinician (1)

John Armstrong, MD
Obstetrics/Gynecology
NPI 1790875995
3434 VILLA LN SUITE 360
Napa, CA 94558
(707) 257-4317
✔ 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 for Provider-Performed Microscopy Procedures (PPMP) 05D0709799

John T Armstrong Jr MD Inc · Napa, CA
Active · expires Nov 1, 2027
CLIA Number05D0709799
Laboratory TypePhysician Office
Certificate Effective DateNovember 2, 2025
Certificate Expiration DateNovember 1, 2027
Laboratory DirectorJohn T. Armstrong MD
Laboratory Phone(707) 257-4317
Laboratory LocationJohn T Armstrong Jr MD Inc3434 Villa Lane Suite 360, Napa, CA 94558
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 John T Armstrong Jr MD Inc's NPI number?

The NPI number for John T Armstrong Jr MD Inc is 1598830564. It was assigned to this organization in the NPPES registry on November 22, 2006.

Where is John T Armstrong Jr MD Inc located?

John T Armstrong Jr MD Inc is located at 3434 Villa Ln Ste 360, Napa, CA 94558. The listed phone number is (707) 257-4317.

What is John T Armstrong Jr MD Inc's specialty?

The primary specialty registered for this NPI is Obstetrics & Gynecology, specializing in Gynecology, with taxonomy code 207VG0400X.

Is John T Armstrong Jr MD Inc enrolled in Medicare?

Yes. John T Armstrong Jr MD Inc is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through John T Armstrong Jr MD Inc?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Obstetrics/Gynecology) reassigns their Medicare billing to John T Armstrong Jr MD Inc. 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 John T Armstrong Jr MD Inc hold a CLIA laboratory certificate?

Yes. A Certificate for Provider-Performed Microscopy Procedures (PPMP) (number 05D0709799) is associated with this NPI, valid through November 1, 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 John T Armstrong Jr MD Inc was last updated on August 28, 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.