2026 NPPES data Nephrology Physician NPI 1346395704 M.D.
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JEFFREY CHEN, M.D.

Nephrology Physician in MONTEREY, 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
3K
Medicare Part D claims · 391 beneficiaries · Nephrology Physician avg: 1K
Generic prescribing
94%
generic claims · 6% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: JEFFREY CHEN, M.D. is a Nephrology Physician ([object Object]) practicing in MONTEREY, California with a Medicare Part D prescribing footprint of 3K claims across 391 beneficiaries — 6% brand-name prescribing .

What stands out: JEFFREY CHEN, M.D. filed 3,080 Medicare Part D claims in 2023 across MONTEREY, California. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

JEFFREY CHEN, M.D. practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).

JEFFREY CHEN, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 01/24/2007

NPI 1346395704

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

3,080 112% 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).

JEFFREY CHEN, M.D. is a Nephrology Physician provider practicing in MONTEREY, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1346395704. 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.

JEFFREY CHEN, M.D. appears in the CMS NPPES registry as a Nephrology Physician provider holding M.D. credentials at 757 PACIFIC STREET, MONTEREY, CA, 93940, with a listed phone of (831) 375-6802. NPI 1346395704 was issued on 01/24/2007. 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 3,080 prescription claims written by this provider, covering 391 Medicare beneficiaries and totaling roughly $274K in drug spend, split 6% brand-name and 94% 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.

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

757 PACIFIC STREET
MONTEREY, CA 93940

Provider Details

NPI 1346395704
Specialty Nephrology Physician
Credentials M.D.
Gender Male
NPI Issued 01/24/2007

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 JEFFREY CHEN, M.D.. To verify JEFFREY CHEN, M.D.'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 · Generic-heavy

JEFFREY CHEN, M.D. — brand share 6.0%
Specialty average (est.)

6% brand-name claims vs 94% generic, on 3,080 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.

3,080
Total Claims
$274K
Total Drug Cost
391
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
6,635
Total Day Supply
197,524
Brand vs Generic
6% brand / 94% generic
Brand Drug Cost
$151K
Generic Drug Cost
$123K
Antibiotic Claims
27

Patient Demographics

Average Patient Age
76.0 years
Avg HCC Risk Score
3.17
Gender Split
49% female / 51% male
Age Distribution
<65: 36, 65-74: 124, 75-84: 153, 85+: 78

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Amlodipine Besylate
328
Carvedilol
286
Losartan Potassium
259
Lisinopril
253
Furosemide
228
Spironolactone
167
Sevelamer Carbonate
147
Doxazosin Mesylate
130
Allopurinol
122
Calcium Acetate
113

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

Nephrology Physician Overview

How JEFFREY CHEN, M.D. 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

JEFFREY CHEN, M.D.'s 3,080 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 JEFFREY CHEN, M.D.'s specialty?
JEFFREY CHEN, M.D. specializes in Nephrology Physician and practices in MONTEREY, California. Credentials: M.D..
How much does JEFFREY CHEN, M.D. prescribe under Medicare Part D?
In 2023, JEFFREY CHEN, M.D. wrote 3,080 Medicare Part D claims totaling $274K in drug costs for 391 beneficiaries.
Where is JEFFREY CHEN, M.D. located?
JEFFREY CHEN, M.D. is located at 757 PACIFIC STREET, MONTEREY, CA, 93940. Phone: (831) 375-6802.
What is JEFFREY CHEN, M.D.'s NPI number?
JEFFREY CHEN, M.D.'s National Provider Identifier (NPI) is 1346395704, issued on 01/24/2007.
Does JEFFREY CHEN, M.D. prescribe more brand-name or generic drugs?
JEFFREY CHEN, M.D.'s prescribing is 6% brand-name and 94% generic drugs by claim count, with $151K 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 JEFFREY CHEN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, JEFFREY CHEN, M.D.'s most frequently prescribed drugs include Amlodipine Besylate, Carvedilol, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JEFFREY CHEN, M.D. accept Medicare?
JEFFREY CHEN, M.D. appears in CMS Medicare data with 3,080 Part D claims and 391 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JEFFREY CHEN, M.D.'s credentials?
JEFFREY CHEN, M.D.'s NPI is 1346395704 with credentials M.D.. 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