2026 NPPES data Nephrology Physician NPI 1649470683 MD
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MAGGIE CHEN, MD

Nephrology Physician in SAN JOSE, 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
4K
Medicare Part D claims · 405 beneficiaries · Nephrology Physician avg: 1K
Generic prescribing
77%
generic claims · 23% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
99.6191/100
▲ 17 pts above national avg 83.1 · [object Object]
Industry payments
$1.1K
46 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: MAGGIE CHEN, MD is a Nephrology Physician ([object Object]) practicing in SAN JOSE, California with a Medicare Part D prescribing footprint of 4K claims across 405 beneficiaries — 23% brand-name prescribing . Their CMS MIPS Final Score of 99.6191/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $1.1K across 46 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: MAGGIE CHEN, MD reported a CMS MIPS final score of 99.6191 out of 100, above the 83.1 national average, and filed 4,379 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

MAGGIE CHEN, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

MAGGIE CHEN, MD at a glance

High performer (top quartile)

NPI registry status

Active

Issued 07/18/2007

NPI 1649470683

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

4,379 201% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

MIPS final score

99.6191/100 16.51910000000001% pts

Exceptional band

vs 83.1 national avg

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

Medicare quality performance — MIPS

MAGGIE CHEN, MD's 2023 MIPS final score plotted against the Nephrology Physician national average

High performer (top quartile)
MIPS Final Score
99.6191/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Nephrology Physician) — 99.6191/100 vs national avg 83.1

0%100%National avg83%99%
MIPS final score (Nephrology Physician) — 99.6191/100 vs national avg 83.1

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).

MAGGIE CHEN, MD is a Nephrology Physician provider practicing in SAN JOSE, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1649470683. 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.

MAGGIE CHEN, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 2360 MCKEE RD, SAN JOSE, CA, 95116, with a listed phone of (408) 729-7128. NPI 1649470683 was issued on 07/18/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHEN 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 4,379 prescription claims written by this provider, covering 405 Medicare beneficiaries and totaling roughly $1.2 million in drug spend, split 23% brand-name and 77% generic by claim count. 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 99.6191/100 for the 2023 performance year (Quality 82.8832, Cost 90.847), compared with the national average of 83.1.

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

2360 MCKEE RD
SAN JOSE, CA 95116

Provider Details

NPI 1649470683
Specialty Nephrology Physician
Credentials MD
Gender Female
NPI Issued 07/18/2007

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

99.6191
Final Score
Avg: 83.1
82.8832
Quality
90.847
Cost
90
Promoting Interoperability

Reporting: Individual

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for MAGGIE CHEN, MD. Source: openpaymentsdata.cms.gov.

Total received

$1.1K

Largest payer

Ardelyx, Inc.

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

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 MAGGIE CHEN, MD. To verify MAGGIE CHEN, 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.

Brand vs generic prescribing mix · Typical

MAGGIE CHEN, MD — brand share 23.0%
Specialty average (est.)

23% brand-name claims vs 77% generic, on 4,379 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

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

4,379
Total Claims
$1.2M
Total Drug Cost
405
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
10,487
Total Day Supply
309,749
Brand vs Generic
23% brand / 77% generic
Brand Drug Cost
$1.1M
Generic Drug Cost
$144K
Antibiotic Claims
23

Patient Demographics

Average Patient Age
77.6 years
Avg HCC Risk Score
2.73
Gender Split
51% female / 49% male
Age Distribution
<65: 29, 65-74: 123, 75-84: 154, 85+: 99

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Losartan Potassium
416
Amlodipine Besylate
341
Allopurinol
276
Farxiga
Dapagliflozin Propanediol
224
Atorvastatin Calcium
135
Metformin Hcl
122
Furosemide
118
Lisinopril
112
Tamsulosin Hcl
105
Simvastatin
103

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

Nephrology Physician Overview

How MAGGIE CHEN, 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

MAGGIE CHEN, MD's 4,379 claims are above 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 CHEN.

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

Frequently Asked Questions

What is MAGGIE CHEN, MD's specialty?
MAGGIE CHEN, MD specializes in Nephrology Physician and practices in SAN JOSE, California. Credentials: MD.
How much does MAGGIE CHEN, MD prescribe under Medicare Part D?
In 2023, MAGGIE CHEN, MD wrote 4,379 Medicare Part D claims totaling $1.2M in drug costs for 405 beneficiaries.
What is MAGGIE CHEN, MD's Medicare quality score?
MAGGIE CHEN, MD has a CMS MIPS Final Score of 99.6191/100 (Quality: 82.8832, Cost: 90.847). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is MAGGIE CHEN, MD located?
MAGGIE CHEN, MD is located at 2360 MCKEE RD, SAN JOSE, CA, 95116. Phone: (408) 729-7128.
What is MAGGIE CHEN, MD's NPI number?
MAGGIE CHEN, MD's National Provider Identifier (NPI) is 1649470683, issued on 07/18/2007.
Does MAGGIE CHEN, MD prescribe more brand-name or generic drugs?
MAGGIE CHEN, MD's prescribing is 23% brand-name and 77% generic drugs by claim count, with $1.1M in brand drug costs.
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 MAGGIE CHEN, MD prescribe most often?
Based on 2023 Medicare Part D data, MAGGIE CHEN, MD's most frequently prescribed drugs include Losartan Potassium, Amlodipine Besylate, Allopurinol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MAGGIE CHEN, MD accept Medicare?
MAGGIE CHEN, MD appears in CMS Medicare data with 4,379 Part D claims and 405 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MAGGIE CHEN, MD's credentials?
MAGGIE CHEN, MD's NPI is 1649470683 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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