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CAROLYN SIU
NPI 1679304448
Physician Assistant in San Mateo, CA

Active since August 12, 2024PECOS EnrolledAccepts Medicare Assignment
50 S SAN MATEO DR FL 4, SAN MATEO, CA 94401(650) 652-8500(650) 652-8501 Get Directions Write a Review

NPPES record last updated: January 13, 2026. Verified against the NPPES registry weekly; last sync: August 02, 2026.

Record update history: Jan 13, 2026, Mar 20, 2025, Mar 3, 2025 and 1 more (4 updates tracked since 2024).

About Carolyn Siu NPPES

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

CAROLYN SIU (NPI 1679304448) is an individual physician assistant in San Mateo, California, licensed in California (PA65879) and active in the NPI registry since August 2024. She is enrolled in Medicare PECOS and is a graduate of Other (2024).

NPPES Registry Identity

NPI1679304448
Entity TypeIndividualFemale
Primary Taxonomy363A00000X
Provider Legal NameCAROLYN SIU
Location Address50 S SAN MATEO DR FL 4San Mateo, CA 94401-3857
Mailing AddressPo Box 276950Sacramento, CA 95827-6950
Phone(650) 652-8500
Fax(650) 652-8501
Sole ProprietorNo
Medical School CMSOtherGraduated 2024
Enumeration DateAugust 12, 2024
Last NPPES UpdateJanuary 13, 20264 updates tracked since enumeration
NPPES CertifiedJanuary 13, 2026
✔ NPI 1679304448 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPhysician AssistantPhysician Assistants & Advanced Practice Nursing Providers
Taxonomy Code363A00000X
License✔ Licensed in CA · PA65879
Definition
A physician assistant is a person who has successfully completed an accredited education program for physician assistant, is licensed by the state and is practicing within the scope of that license. Physician assistants are formally trained to perform many of the routine, time-consuming tasks a physician can do. In some states, they may prescribe medications. They take medical histories, perform physical exams, order lab tests and x-rays, and give inoculations. Most states require that they work under the supervision of a physician.
50 S SAN MATEO DR FL 4, San Mateo, CA 94401
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Carolyn Siu 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.

PECOS PAC ID7214459791
PECOS Enrollment IDI20250314000094
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.

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94401 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
$104.51 typical visit price
range $69.00 – $202.35
Typical copayment $26.12 (range $17.25 – $50.58)
Most-billed visit code 99203
Established Patient
$84.91 typical visit price
range $23.44 – $166.46
Typical copayment $21.22 (range $5.86 – $41.61)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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 Carolyn Siu's NPI number?

The NPI number for Carolyn Siu is 1679304448. It was assigned to this individual provider in the NPPES registry on August 12, 2024.

Where is Carolyn Siu located?

Carolyn Siu practices at 50 S San Mateo Dr Fl 4, San Mateo, CA 94401. The listed phone number is (650) 652-8500.

What is Carolyn Siu's specialty?

The primary specialty registered for this NPI is Physician Assistant with taxonomy code 363A00000X.

Is Carolyn Siu enrolled in Medicare?

Yes. Carolyn Siu 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.

When was this NPI record last updated?

The NPPES record for Carolyn Siu was last updated on January 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 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.