VIVIAN TO DO
NPI 1043899230
Hospitalist in Downey, CA
About Vivian To Do NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
VIVIAN TO DO (NPI 1043899230) is an individual hospitalist provider in Downey, California, licensed in California (20A21692) and active in the NPI registry since April 2021. She is enrolled in Medicare PECOS and is a graduate of West Virginia School Of Osteopathic Medicine (2021).
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
Vivian To Do 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 Vivian To reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Downey, CA 90241
- Reassigned Medicare billing, California enrollment
- 840 clinicians in this Medicare group
Alhambra, CA 91801
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Apollomed Hospitalists A Medical Corporation
- 53 clinicians in this Medicare group
Los Angeles, CA 90015
- Reassigned Medicare billing, California enrollment
- 2,052 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 4
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 90241 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.
DOWNEY, CA 90241
DOWNEY, CA 90241
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 To's NPI number?
The NPI number for Vivian To is 1043899230. It was assigned to this individual provider in the NPPES registry on April 5, 2021.
Where is Vivian To located?
Vivian To practices at 11500 Brookshire Ave, Downey, CA 90241. The listed phone number is (562) 904-5000.
What is Vivian To's specialty?
The primary specialty registered for this NPI is Hospitalist with taxonomy code 208M00000X.
Is Vivian To enrolled in Medicare?
Yes. Vivian To 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 To's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Vivian To reassigns Medicare benefits to 3 organizations: Pih Health Physicians (Downey, CA), Astrana Care Hospitalists, A Medical Corporation (Alhambra, CA) and Healthcare Partners Affiliates Medical Group (Los Angeles, 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 To'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 To was last updated on October 29, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 months 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.
# Vivian To, DO · NPI 1043899230
Hospitalist physician in Downey, California. Individual provider, active in the CMS NPPES registry since April 5, 2021.
## Identity
- **NPI:** 1043899230 (Entity type: Individual)
- **Enumerated:** April 5, 2021
- **Primary specialty:** Hospitalist · taxonomy 208M00000X
- **State license:** 20A21692 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 11500 BROOKSHIRE AVE, Downey, CA 90241-4917
- **Phone:** (562) 904-5000
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health
- **Bills Medicare through:** 3 organizations under Medicare reassignment (form CMS-855R): Pih Health Physicians (NPI 1447931506, Downey, CA); Astrana Care Hospitalists, A Medical Corporation (NPI 1265658595, Alhambra, CA); Healthcare Partners Affiliates Medical Group (NPI 1659312593, Los Angeles, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** West Virginia School Of Osteopathic Medicine, class of 2021
## Record status
- **NPPES last updated:** October 29, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1043899230) · Data from the CMS NPPES public registry.