2026 NPPES data Nephrology Physician NPI 1144308230 MD
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SYLVIA CHI-WU, MD

Nephrology Physician in WALNUT CREEK, California. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
1K
Medicare Part D claims · 170 beneficiaries · Nephrology Physician avg: 1K
What the federal data reveals: SYLVIA CHI-WU, MD is a Nephrology Physician ([object Object]) practicing in WALNUT CREEK, California with a Medicare Part D prescribing footprint of 1K claims across 170 beneficiaries .

What stands out: SYLVIA CHI-WU, MD filed 1,080 Medicare Part D claims in 2023 across WALNUT CREEK, California. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

SYLVIA CHI-WU, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

SYLVIA CHI-WU, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 11/02/2006

NPI 1144308230

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

1,080 26% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

Specialty distribution in California

How Nephrology Physician compares to other specialties among California providers

California providers

Nephrology Physician share within California

1. Nephrology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Nephrology Physician share within California

Specialty board-certification context

Estimated specialty board-certified rate — Nephrology Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Nephrology Physician ABMS/AOA estimate

Est. board-certified rate (Nephrology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Nephrology Physician) — ABMS / AOA estimate

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

SYLVIA CHI-WU, MD is a Nephrology Physician provider practicing in WALNUT CREEK, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1144308230. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

SYLVIA CHI-WU, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 1425 S MAIN ST, WALNUT CREEK, CA, 94596, with a listed phone of (925) 295-4000. NPI 1144308230 was issued on 11/02/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHI-WU most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 1,080 prescription claims written by this provider, covering 170 Medicare beneficiaries and totaling roughly $82K in drug spend. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Nephrology Physician is a mid-sized specialty nationwide, with 10,534 enrolled providers across 55 states and an average of 1,454 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

1425 S MAIN ST
WALNUT CREEK, CA 94596

Provider Details

NPI 1144308230
Specialty Nephrology Physician
Credentials MD
Gender Female
NPI Issued 11/02/2006

Hospital and facility affiliations

Facilities where SYLVIA CHI-WU, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

PERMANENTE MEDICAL GROUP INC
WALNUT CREEK, CA

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

License & disciplinary context — California MBC 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~150K California medical licensees in 2023 — they are NOT specific to SYLVIA CHI-WU, MD. To verify SYLVIA CHI-WU, MD's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases

MBC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

1,080
Total Claims
$82K
Total Drug Cost
170
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
2,945
Total Day Supply
86,182
Generic Drug Cost
$47K
Antibiotic Claims
27

Patient Demographics

Average Patient Age
72.3 years
Avg HCC Risk Score
4.68
Gender Split
47% female / 53% male
Age Distribution
<65: 25, 65-74: 72, 75-84: 55, 85+: 18

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Furosemide
93
Losartan Potassium
62
Amlodipine Besylate
60
Allopurinol
47
Terazosin Hcl
44
Lisinopril
42
Metoprolol Succinate
38
Calcitriol
31
Jardiance
Empagliflozin
31
Sevelamer Carbonate
29

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Nephrology Physician Overview

How SYLVIA CHI-WU, MD fits within the Nephrology Physician landscape nationally.

10,534
Nephrology Physician Providers in US
55
States with Nephrology Physician
1,454
Avg Claims per Provider

SYLVIA CHI-WU, MD's 1,080 claims are below the specialty average of 1,454.

Nearby Nephrology Physician Providers in California

Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as CHI-WU.

Compare Nephrology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is SYLVIA CHI-WU, MD's specialty?
SYLVIA CHI-WU, MD specializes in Nephrology Physician and practices in WALNUT CREEK, California. Credentials: MD.
How much does SYLVIA CHI-WU, MD prescribe under Medicare Part D?
In 2023, SYLVIA CHI-WU, MD wrote 1,080 Medicare Part D claims totaling $82K in drug costs for 170 beneficiaries.
Where is SYLVIA CHI-WU, MD located?
SYLVIA CHI-WU, MD is located at 1425 S MAIN ST, WALNUT CREEK, CA, 94596. Phone: (925) 295-4000.
What is SYLVIA CHI-WU, MD's NPI number?
SYLVIA CHI-WU, MD's National Provider Identifier (NPI) is 1144308230, issued on 11/02/2006.
How many Nephrology Physician providers are there in the US?
There are 10,534 Nephrology Physician providers across 55 states in the US. The average Nephrology Physician provider writes 1,454 Medicare Part D claims per year.
What drugs does SYLVIA CHI-WU, MD prescribe most often?
Based on 2023 Medicare Part D data, SYLVIA CHI-WU, MD's most frequently prescribed drugs include Furosemide, Losartan Potassium, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does SYLVIA CHI-WU, MD accept Medicare?
SYLVIA CHI-WU, MD appears in CMS Medicare data with 1,080 Part D claims and 170 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify SYLVIA CHI-WU, MD's credentials?
SYLVIA CHI-WU, MD's NPI is 1144308230 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology