JUSTIN CHEN, MD
Nephrology Physician in PASADENA, California. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.
What stands out: JUSTIN CHEN, MD reported a CMS MIPS final score of 44.1833 out of 100, below the 83.1 national average, and filed 780 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.
JUSTIN CHEN, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
JUSTIN CHEN, MD at a glance
Below national averagePrimary specialty
Medicare Part D claims
MIPS final score
Specialty distribution in California
How Nephrology Physician compares to other specialties among California providers
Nephrology Physician share within California
Nephrology Physician is one of the more visible NUCC categories in California
Each bar reflects the share of in-state providers whose primary NUCC taxonomy matches the specialty. Long tail of ~690 NUCC codes folded into "Other" to keep the comparison legible.
Medicare quality performance — MIPS
JUSTIN CHEN, MD's 2023 MIPS final score plotted against the Nephrology Physician national average
- MIPS Final Score
- 44.1833/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Nephrology Physician) — 44.1833/100 vs national avg 83.1
Quality benchmarks
- National MIPS avg 2023 reporting year
- Quality dim CMS Quality category
- Cost dim CMS Cost category
- Specialty volume Nephrology Physician US NPIs
44.1833/100 MIPS final score — 38.9 pts below the 83.1 national average
Quality, Cost, Promoting Interoperability, and Improvement Activities composite score for the 2023 performance year. Specialty: Nephrology Physician. Quality dim: 54.2105. Cost dim: 41.6635.
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).
JUSTIN CHEN, MD is a Nephrology Physician provider practicing in PASADENA, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1447526066. 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.
JUSTIN CHEN, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 301 S FAIR OAKS AVE STE 405, PASADENA, CA, 91105, with a listed phone of (626) 352-0010. NPI 1447526066 was issued on 03/28/2012. 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 780 prescription claims written by this provider, covering 148 Medicare beneficiaries and totaling roughly $246K in drug spend, split 17% brand-name and 83% 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 44.1833/100 for the 2023 performance year (Quality 54.2105, Cost 41.6635), 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
Provider Details
| NPI | 1447526066 |
|---|---|
| Specialty | Nephrology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 03/28/2012 |
Verify this provider's license
PlainDoctor pulls this profile from the CMS NPPES public registry. Confirm JUSTIN CHEN, MD's current license status, disciplinary history, and board certifications with the Medical Board of California in California before relying on this page for a clinical or care decision.
How we sourced this profile
CMS Quality Score (MIPS)
Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.
Reporting: Individual
Hospital and facility affiliations
Facilities where JUSTIN CHEN, 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.
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 JUSTIN CHEN, MD. To verify JUSTIN CHEN, MD's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
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
17% brand-name claims vs 83% generic, on 780 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.
Prescribing Breakdown
- 30-Day Fills
- 1,696
- Total Day Supply
- 49,508
- Brand vs Generic
- 17% brand / 83% generic
- Brand Drug Cost
- $214K
- Generic Drug Cost
- $32K
Patient Demographics
- Average Patient Age
- 73.3 years
- Avg HCC Risk Score
- 5.41
- Gender Split
- 43% female / 57% male
- Age Distribution
- <65: 31, 65-74: 36, 75-84: 52, 85+: 29
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 | 62 |
| Furosemide | 52 |
| Hydralazine Hcl | 44 |
| Losartan Potassium | 43 |
| Carvedilol | 34 |
| Hydrochlorothiazide | 33 |
| Sevelamer Carbonate | 30 |
| Lisinopril | 26 |
| Lokelma Sodium Zirconium Cyclosilicate | 26 |
| Nifedipine Er Nifedipine | 25 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Nephrology Physician Overview
How JUSTIN CHEN, MD fits within the Nephrology Physician landscape nationally.
JUSTIN CHEN, MD's 780 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 CHEN.
Compare Nephrology Physician nationally: see state-by-state distribution →
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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