ASHISH ATREJA MD
NPI 1831152883
Internal Medicine - Gastroenterology in Stanford, CA
About Ashish Atreja Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ASHISH ATREJA MD (NPI 1831152883) is an individual gastroenterology provider in Stanford, California, licensed in California (C184563) and active in the NPI registry since April 2006. He is enrolled in Medicare PECOS, maintains a secondary practice location in New York, and is a graduate of Other (1999).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
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
Ashish Atreja Md 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 Reassignments
6Medicare enrollment records show Ashish Atreja reassigns Medicare billing to 6 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Stanford, CA 94305
- Reassigned Medicare billing, California enrollment
- 4,258 clinicians in this Medicare group
Palo Alto, CA 94304
- Reassigned Medicare billing, California enrollment
- 3,617 clinicians in this Medicare group
Elk Grove, CA 95758
- Reassigned Medicare billing, California enrollment
- 918 clinicians in this Medicare group
Davis, CA 95616
- Reassigned Medicare billing, California enrollment
- 2,570 clinicians in this Medicare group
Davis, CA 95616
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Fusioncareai-Ca PC
New York, NY 10029
- Reassigned Medicare billing, New York enrollment
- 104 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 94305 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 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
STANFORD, CA 94305
STANFORD, CA 94305
STANFORD, CA 94305
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 Ashish Atreja's NPI number?
The NPI number for Ashish Atreja is 1831152883. It was assigned to this individual provider in the NPPES registry on April 10, 2006.
Where is Ashish Atreja located?
Ashish Atreja practices at 300 Pasteur Dr, Stanford, CA 94305. The listed phone number is (650) 723-4000.
What is Ashish Atreja's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.
Is Ashish Atreja enrolled in Medicare?
Yes. Ashish Atreja 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 organizations bill Medicare for Ashish Atreja's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Ashish Atreja reassigns Medicare benefits to 6 organizations: Stanford Health Care (Stanford, CA), Lpch Medical Group Div Of Lucile (Palo Alto, CA), Regents Of The University Of California (Elk Grove, CA), Regents Of The Univ Of Ca (Davis, CA), Fusioncareai-Ca, P.C. (Davis, CA) and 1 more organization, listed in the Medicare section above. Each 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 Ashish Atreja'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 Ashish Atreja was last updated on January 22, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 9 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.
# Ashish Atreja, MD · NPI 1831152883
Gastroenterology physician in Stanford, California. Individual provider, active in the CMS NPPES registry since April 10, 2006.
## Identity
- **NPI:** 1831152883 (Entity type: Individual)
- **Enumerated:** April 10, 2006
- **Primary specialty:** Internal Medicine - Gastroenterology · taxonomy 207RG0100X
- **State license:** C184563 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 300 PASTEUR DR, Stanford, CA 94305-2200
- **Phone:** (650) 723-4000
## 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:** 6 organizations under Medicare reassignment (form CMS-855R): Stanford Health Care (NPI 1437292927, Stanford, CA); Lpch Medical Group Div Of Lucile (NPI 1417907940, Palo Alto, CA); Regents Of The University Of California (NPI 1174966071, Elk Grove, CA); Regents Of The Univ Of Ca (NPI 1053304071, Davis, CA); Fusioncareai-Ca, P.C. (NPI 1174482913, Davis, CA); and 1 more · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 1999
## Record status
- **NPPES last updated:** January 22, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1831152883) · Data from the CMS NPPES public registry.