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VIVIEN KON-EA SUN MD
NPI 1902243520
Hospitalist in Palo Alto, CA

Active since May 23, 2013PECOS Enrolled
725 WELCH RD, PALO ALTO, CA 94304(650) 497-8000 Get Directions Write a Review

NPPES record last updated: April 28, 2024. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Apr 28, 2024, Apr 25, 2017 (2 updates tracked since 2017).

About Vivien Kon-ea Sun Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

VIVIEN KON-EA SUN MD (NPI 1902243520) is an individual hospitalist provider in Palo Alto, California, licensed in California (A134552) and active in the NPI registry since May 2013. She is enrolled in Medicare PECOS and maintains a secondary practice location in San Francisco.

NPPES Registry Identity

NPI1902243520
Entity TypeIndividualFemale
Primary Taxonomy208M00000X
Provider Legal NameVIVIEN KON-EA SUNCredential: MD
Location Address725 WELCH RDPalo Alto, CA 94304-1601
Mailing Address505 Parnassus Ave Box 0110San Francisco, CA 94143-0110
Phone(650) 497-8000
Sole ProprietorNo
Enumeration DateMay 23, 2013
Last NPPES UpdateApril 28, 20242 updates tracked since enumeration
NPPES CertifiedApril 28, 2024
✔ NPI 1902243520 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyHospitalistAllopathic & Osteopathic Physicians
Taxonomy Code208M00000X
License✔ Licensed in CA · A134552
Definition
Hospitalists are physicians whose primary professional focus is the general medical care of hospitalized patients. Their activities include patient care, teaching, research, and leadership related to Hospital Medicine. The term 'hospitalist' refers to physicians whose practice emphasizes providing care for hospitalized patients.
Also ListedPediatricsTaxonomy 208000000X · License A134552 (CA)
725 WELCH RD, Palo Alto, CA 94304
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Secondary Practice Location 1

Location 1505 Parnassus Ave Box 0110San Francisco, CA 94143-0110 · Phone (415) 476-5001

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Vivien Kon-ea Sun Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

3

Medicare enrollment records show Vivien Sun reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Lpch Medical Group Div Of Lucile
Same address
Children
725 WELCH RD
Palo Alto, CA 94304
  • Reassigned Medicare billing, California enrollment
  • 3,617 clinicians in this Medicare group
NPI 1417907940 (650) 498-6762
Stanford Health Care
0.2 mi
General Acute Care Hospital
300 PASTEUR DRIVE
Stanford, CA 94305
  • Reassigned Medicare billing, California enrollment
  • 4,258 clinicians in this Medicare group
NPI 1437292927 (650) 723-4000
University Of California Sfgh Medical Group
25 mi
Endocrinology, Diabetes & Metabolism
2540 23RD ST, 2ND FLOOR, ROOM 2110
San Francisco, CA 94143
  • Reassigned Medicare billing, California enrollment
  • 637 clinicians in this Medicare group
NPI 1265407381 (415) 514-9031

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 94304 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$156.67 typical visit price
range $70.37 – $206.04
Typical copayment $39.16 (range $17.59 – $51.51)
Most-billed visit code 99204
Established Patient
$121.77 typical visit price
range $23.96 – $169.60
Typical copayment $30.44 (range $5.99 – $42.40)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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.

EIRI INENAGA MS, OTR/L
Occupational Therapist (Pediatrics)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8218
WENDY LEIGH ADAMS ARNP
Nurse Practitioner (Neonatal)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
KEVIN WEI-HAN CHI MD
Pediatrics
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
ASHEEN RAMA MD
Anesthesiology (Pediatric Anesthesiology)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
CRYSTAL LEE MACKALL MD
Pediatrics (Pediatric Hematology-Oncology)
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
KRISTI LYNNE O'CONNOR OT
Occupational Therapist
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
LAUREN GENNA ROOS NP
Nurse Practitioner
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000
SHALINI MITTAL MD
Hospitalist
725 WELCH RD
PALO ALTO, CA 94304
Santa Clara County (650) 497-8000

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 Vivien Sun's NPI number?

The NPI number for Vivien Sun is 1902243520. It was assigned to this individual provider in the NPPES registry on May 23, 2013.

Where is Vivien Sun located?

Vivien Sun practices at 725 Welch Rd, Palo Alto, CA 94304. The listed phone number is (650) 497-8000.

What is Vivien Sun's specialty?

The primary specialty registered for this NPI is Hospitalist with taxonomy code 208M00000X.

Is Vivien Sun enrolled in Medicare?

Yes. Vivien Sun is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Vivien Sun's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Vivien Sun reassigns Medicare benefits to 3 organizations: Lpch Medical Group Div Of Lucile (Palo Alto, CA), Stanford Health Care (Stanford, CA) and University Of California Sfgh Medical Group (San Francisco, 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 Vivien Sun'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 Vivien Sun was last updated on April 28, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.