WALTER S. TJOA MD
NPI 1801955463
Dermatology in Fontana, CA
About Walter S. Tjoa Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
WALTER S. TJOA MD (NPI 1801955463) is an individual dermatology provider in Fontana, California, licensed in California (C42142) and active in the NPI registry since December 2006. He is enrolled in Medicare PECOS.
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 (PECOS)
Walter S. Tjoa Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignment
Medicare enrollment records show Walter Tjoa 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
- 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 92335 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.
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 Walter Tjoa's NPI number?
The NPI number for Walter Tjoa is 1801955463. It was assigned to this individual provider in the NPPES registry on December 8, 2006.
Where is Walter Tjoa located?
Walter Tjoa practices at 9961 Sierra Ave, Fontana, CA 92335. The listed phone number is (909) 427-3910.
What is Walter Tjoa's specialty?
The primary specialty registered for this NPI is Dermatology with taxonomy code 207N00000X.
Is Walter Tjoa enrolled in Medicare?
Yes. Walter Tjoa is registered in the Medicare PECOS enrollment system.
Which organization bills Medicare for Walter Tjoa's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Walter Tjoa 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 Walter Tjoa'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 Walter Tjoa was last updated on November 18, 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.