WALTER W CHIEN MD
NPI 1386615631
Internal Medicine - Clinical Cardiac Electrophysiology in Stockton, CA
About Walter W Chien Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
WALTER W CHIEN MD (NPI 1386615631) is an individual clinical cardiac electrophysiology provider in Stockton, California, licensed in California (G56242) and active in the NPI registry since January 2006. He is enrolled in Medicare PECOS and is a graduate of Washington University School Of Medicine (1984).
NPPES Registry Identity
Specialties & Licenses 2
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
Walter W Chien 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
3Medicare enrollment records show Walter Chien reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Stockton, CA 95202
- Reassigned Medicare billing, California enrollment
- 534 clinicians in this Medicare group
French Camp, CA 95231
- Reassigned Medicare billing, California enrollment
- 512 clinicians in this Medicare group
Milpitas, CA 95035
- Reassigned Medicare billing, California enrollment
- Also billed through NPI 1043354020 (California), NPI 1629301346 (California)
- 2,460 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 95204 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
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 Chien's NPI number?
The NPI number for Walter Chien is 1386615631. It was assigned to this individual provider in the NPPES registry on January 26, 2006.
Where is Walter Chien located?
Walter Chien practices at 2800 N California St Ste 8, Stockton, CA 95204. The listed phone number is (209) 938-0232.
What is Walter Chien's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Clinical Cardiac Electrophysiology, with taxonomy code 207RC0001X.
Is Walter Chien enrolled in Medicare?
Yes. Walter Chien 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 Walter Chien's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Walter Chien reassigns Medicare benefits to 3 organizations: County Of San Joaquin (Stockton, CA), San Joaquin Faculty Medical Group (French Camp, CA) and County Of Santa Clara (Milpitas, CA). 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 Walter Chien'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 Chien was last updated on November 4, 2022. 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.
# Walter W Chien, MD · NPI 1386615631
Clinical Cardiac Electrophysiology physician in Stockton, California. Individual provider, active in the CMS NPPES registry since January 26, 2006.
## Identity
- **NPI:** 1386615631 (Entity type: Individual)
- **Enumerated:** January 26, 2006
- **Primary specialty:** Internal Medicine - Clinical Cardiac Electrophysiology · taxonomy 207RC0001X
- **State license:** G56242 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 2800 N CALIFORNIA ST STE 8, Stockton, CA 95204-3759
- **Phone:** (209) 938-0232 · **Fax:** (209) 938-0233
## 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:** 3 organizations under Medicare reassignment (form CMS-855R): County Of San Joaquin (NPI 1891036612, Stockton, CA); San Joaquin Faculty Medical Group (NPI 1225063761, French Camp, CA); County Of Santa Clara (NPI 1285629899, Milpitas, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Washington University School Of Medicine, class of 1984
## Record status
- **NPPES last updated:** November 4, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1386615631) · Data from the CMS NPPES public registry.