VIVIAN TSAI M.D.
NPI 1770534182
Internal Medicine - Cardiovascular Disease in Fremont, CA
About Vivian Tsai M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
VIVIAN TSAI M.D. (NPI 1770534182) is an individual cardiovascular disease provider in Fremont, California, licensed in California (A88245) and active in the NPI registry since May 2006. She is enrolled in Medicare PECOS and is a graduate of Johns Hopkins University School Of Medicine (2003).
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
Vivian Tsai M.d. 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
2Medicare enrollment records show Vivian Tsai reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Fremont, CA 94538
- Reassigned Medicare billing, California enrollment
- 68 clinicians in this Medicare group
Palo Alto, CA 94301
- Reassigned Medicare billing, California enrollment
- 4,479 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 24
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 94538 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 13
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
FREMONT, CA 94538
FREMONT, CA 94538
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 Vivian Tsai's NPI number?
The NPI number for Vivian Tsai is 1770534182. It was assigned to this individual provider in the NPPES registry on May 12, 2006.
Where is Vivian Tsai located?
Vivian Tsai practices at 3200 Kearney Street, Fremont, CA 94538. The listed phone number is (510) 490-1222.
What is Vivian Tsai's specialty?
The primary specialty registered for this NPI is Internal Medicine, specializing in Cardiovascular Disease, with taxonomy code 207RC0000X.
Is Vivian Tsai enrolled in Medicare?
Yes. Vivian Tsai 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 Vivian Tsai's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Vivian Tsai reassigns Medicare benefits to 2 organizations: Washington Township Hospital District (Fremont, CA) and Sutter Bay Medical Foundation (Palo Alto, 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 Vivian Tsai'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 Vivian Tsai was last updated on May 28, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 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.