DR. ANDREW MARK GREGG MD PHD
NPI 1942769104
Internal Medicine - Gastroenterology in Thousand Oaks, CA
About Dr. Andrew Mark Gregg Md Phd NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. ANDREW MARK GREGG MD PHD (NPI 1942769104) is an individual gastroenterology provider in Thousand Oaks, California, licensed in California (A177654) and active in the NPI registry since March 2019. He is enrolled in Medicare PECOS and is a graduate of Other (2019).
NPPES Registry Identity
Specialties & Licenses
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Dr. Andrew Mark Gregg Md Phd is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignment
Medicare enrollment records show Andrew Gregg reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
West Hills, CA 91307
- Reassigned Medicare billing, California enrollment
- Also billed through NPI 1235107566 (California), NPI 1366041469 (California)
- 52 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 91361 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 2
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
THOUSAND OAKS, CA 91361
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 Andrew Gregg's NPI number?
The NPI number for Andrew Gregg is 1942769104. It was assigned to this individual provider in the NPPES registry on March 18, 2019.
Where is Andrew Gregg located?
Andrew Gregg practices at 248 Hampshire Rd Ste 200, Thousand Oaks, CA 91361. The listed phone number is (805) 370-0127.
What is Andrew Gregg's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.
Is Andrew Gregg enrolled in Medicare?
Yes. Andrew Gregg is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organization bills Medicare for Andrew Gregg's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Andrew Gregg reassigns Medicare benefits to The Regents Of The University Of California (West Hills, CA). The 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 Andrew Gregg's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Andrew Gregg was last updated on August 4, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 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.
# Dr. Andrew Mark Gregg, MD PHD · NPI 1942769104
Gastroenterology physician in Thousand Oaks, California. Individual provider, active in the CMS NPPES registry since March 18, 2019.
## Identity
- **NPI:** 1942769104 (Entity type: Individual)
- **Enumerated:** March 18, 2019
- **Primary specialty:** Internal Medicine - Gastroenterology · taxonomy 207RG0100X
- **State license:** A177654 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 248 HAMPSHIRE RD STE 200, Thousand Oaks, CA 91361-2401
- **Phone:** (805) 370-0127
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** The Regents Of The University Of California (NPI 1215381843, West Hills, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2019
## Record status
- **NPPES last updated:** August 4, 2025
---
Source: [NPI Profile](https://npiprofile.com/npi/1942769104) · Data from the CMS NPPES public registry.