DR. JOHN L CHEN D.O.
NPI 1649356023
Anesthesiology in Fontana, CA
About Dr. John L Chen D.o. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. JOHN L CHEN D.O. (NPI 1649356023) is an individual anesthesiology provider in Fontana, California, licensed in California (20A9401) and active in the NPI registry since October 2006. He is enrolled in Medicare PECOS and is a graduate of Other (2003).
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 L Chen D.o. 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 Chen reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Fontana, CA 92335
- Reassigned Medicare billing, California enrollment
- Also billed through NPI 1952333460 (California)
- 5,228 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.
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.
FONTANA, CA 92335
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 Chen's NPI number?
The NPI number for John Chen is 1649356023. It was assigned to this individual provider in the NPPES registry on October 28, 2006.
Where is John Chen located?
John Chen practices at 9961 Sierra Ave, Fontana, CA 92335. The listed phone number is (909) 427-2673.
What is John Chen's specialty?
The primary specialty registered for this NPI is Anesthesiology with taxonomy code 207L00000X.
Is John Chen enrolled in Medicare?
Yes. John Chen 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 Chen's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Chen reassigns Medicare benefits to Southern California Permanente Medical Group (Fontana, 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 Chen'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 Chen was last updated on November 30, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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 L Chen, D.O. · NPI 1649356023
Anesthesiology physician in Fontana, California. Individual provider, active in the CMS NPPES registry since October 28, 2006.
## Identity
- **NPI:** 1649356023 (Entity type: Individual)
- **Enumerated:** October 28, 2006
- **Primary specialty:** Anesthesiology · taxonomy 207L00000X
- **State license:** 20A9401 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 9961 SIERRA AVE, Fontana, CA 92335-6720
- **Phone:** (909) 427-2673 · **Fax:** (909) 427-5219
## 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:** Southern California Permanente Medical Group (NPI 1689606196, Fontana, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2003
## Record status
- **NPPES last updated:** November 30, 2021
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Source: [NPI Profile](https://npiprofile.com/npi/1649356023) · Data from the CMS NPPES public registry.