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ADVANCED GASTROENTEROLOGY, INC.
NPI 1497970875
Internal Medicine - Gastroenterology in Thousand Oaks, CA

Active since April 13, 2007
555 MARIN ST STE 270, THOUSAND OAKS, CA 91360(805) 719-0244(805) 777-1730 Get Directions Write a Review

NPPES record last updated: February 11, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Advanced Gastroenterology, Inc. NPPES

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

ADVANCED GASTROENTEROLOGY, INC. (NPI 1497970875) is a healthcare organization registered as a gastroenterology in Thousand Oaks, California and active in the NPI registry since April 2007. The organization lists Gilbert Simoni, Owner, as its authorized official.

NPPES Registry Identity

NPI1497970875
Entity TypeOrganization
Primary Taxonomy207RG0100X
Legal Business NameADVANCED GASTROENTEROLOGY, INC.
Location Address555 MARIN ST STE 270Thousand Oaks, CA 91360-4112
Mailing Address555 Marin St Ste 270Thousand Oaks, CA 91360-4112 · (805) 719-0244 · Fax (805) 777-1730
Phone(805) 719-0244
Fax(805) 777-1730
Organization SubpartNo
Authorized OfficialGilbert SimoniOwner · (805) 719-0244
Enumeration DateApril 13, 2007
Last NPPES UpdateFebruary 11, 2025
NPPES CertifiedFebruary 11, 2025
✔ NPI 1497970875 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 CA · A77140
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.
555 MARIN ST STE 270, Thousand Oaks, CA 91360
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Other Names 1

Other NameAgi

Other Identifiers 1

OtherW20758CA · Medicare Group Id

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)

Advanced Gastroenterology, Inc. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

2

Medicare enrollment records show 2 clinicians reassign Medicare billing to Advanced Gastroenterology, Inc., which bills Medicare for the services they deliver. Of these, 1 practice at this address and 2 within 10 miles. They are listed nearest first.

Clinicians, nearest first (2)

Gilbert Simoni, M.D., FACG
Gastroenterology
NPI 1316922958
555 MARIN ST STE 270
Thousand Oaks, CA 91360
(805) 719-0244
✔ PECOSSame address
Fernanda Monteon Ibarra, AGACNP-BC
Nurse Practitioner
NPI 1851990550
30222 BELMONT CT
Agoura Hills, CA 91301
(818) 282-4054
✔ PECOS6.0 mi

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

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 Advanced Gastroenterology, Inc.'s NPI number?

The NPI number for Advanced Gastroenterology, Inc. is 1497970875. It was assigned to this organization in the NPPES registry on April 13, 2007. The provider is also known as Agi.

Where is Advanced Gastroenterology, Inc. located?

Advanced Gastroenterology, Inc. is located at 555 Marin St Ste 270, Thousand Oaks, CA 91360. The listed phone number is (805) 719-0244.

What is Advanced Gastroenterology, Inc.'s specialty?

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

Is Advanced Gastroenterology, Inc. enrolled in Medicare?

Yes. Advanced Gastroenterology, Inc. is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Advanced Gastroenterology, Inc.?

According to the CMS Revalidation Reassignment List (October 2026 release), 2 clinicians reassign their Medicare billing to Advanced Gastroenterology, Inc., in Gastroenterology and Nurse Practitioner. 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, 1 practice at this address and 2 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Advanced Gastroenterology, Inc. was last updated on February 11, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 20 months 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.