DR. JOHN TZU-YU CHANG MD
NPI 1265594527
Internal Medicine - Gastroenterology in San Diego, CA
About Dr. John Tzu-yu Chang Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. JOHN TZU-YU CHANG MD (NPI 1265594527) is an individual gastroenterology provider in San Diego, California, licensed in California (A110350) and active in the NPI registry since December 2006. He is enrolled in Medicare PECOS and is a graduate of Temple University School Of Medicine (2001).
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. John Tzu-yu Chang 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 Reassignment
Medicare enrollment records show John Chang reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
San Diego, CA 92103
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Regents Of The University Of California
- 1,051 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.
Areas of Expertise CMS Part B claims 6
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 92103 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.
SAN DIEGO, CA 92103
SAN DIEGO, CA 92103
SAN DIEGO, CA 92103
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 Chang's NPI number?
The NPI number for John Chang is 1265594527. It was assigned to this individual provider in the NPPES registry on December 14, 2006.
Where is John Chang located?
John Chang practices at 200 W Arbor Dr, San Diego, CA 92103. The listed phone number is (800) 926-8273.
What is John Chang's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Gastroenterology, with taxonomy code 207RG0100X.
Is John Chang enrolled in Medicare?
Yes. John Chang 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 John Chang's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Chang reassigns Medicare benefits to Regents Of The University Of California - Ucsd Medical Group (San Diego, 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 John Chang'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 John Chang was last updated on August 21, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.
# Dr. John Tzu-Yu Chang, MD · NPI 1265594527
Gastroenterology physician in San Diego, California. Individual provider, active in the CMS NPPES registry since December 14, 2006.
## Identity
- **NPI:** 1265594527 (Entity type: Individual)
- **Enumerated:** December 14, 2006
- **Primary specialty:** Internal Medicine - Gastroenterology · taxonomy 207RG0100X
- **State license:** A110350 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 200 W ARBOR DR, San Diego, CA 92103-9000
- **Phone:** (800) 926-8273
## 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:** Regents Of The University Of California - Ucsd Medical Group (NPI 1336267137, San Diego, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Temple University School Of Medicine, class of 2001
## Record status
- **NPPES last updated:** August 21, 2023
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Source: [NPI Profile](https://npiprofile.com/npi/1265594527) · Data from the CMS NPPES public registry.