2026 NPPES data Nephrology Physician NPI 1508868787 MD
Verify on CMS →

CHANG JOO, MD

Nephrology Physician in MODESTO, 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
2K
Medicare Part D claims · 344 beneficiaries · Nephrology Physician avg: 1K
MIPS score
100/100
▲ 17 pts above national avg 83.1 · [object Object]
Industry payments
$44.75
2 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: CHANG JOO, MD is a Nephrology Physician ([object Object]) practicing in MODESTO, California with a Medicare Part D prescribing footprint of 2K claims across 344 beneficiaries . Their CMS MIPS Final Score of 100/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $44.75 across 2 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: CHANG JOO, MD reported a CMS MIPS final score of 100 out of 100, above the 83.1 national average, and filed 1,771 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)

CHANG JOO, 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).

CHANG JOO, MD at a glance

High performer (top quartile)

NPI registry status

Active

Issued 06/01/2005

NPI 1508868787

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

1,771 22% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

MIPS final score

100/100 16.900000000000006% 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

CHANG JOO, MD's 2023 MIPS final score plotted against the Nephrology Physician national average

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

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

0%100%National avg83%99%
MIPS final score (Nephrology Physician) — 100/100 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).

CHANG JOO, MD is a Nephrology Physician provider practicing in MODESTO, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1508868787. 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.

CHANG JOO, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 305 E GRANGER AVE, MODESTO, CA, 95350, with a listed phone of (209) 526-1606. NPI 1508868787 was issued on 06/01/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what JOO 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 1,771 prescription claims written by this provider, covering 344 Medicare beneficiaries and totaling roughly $332K 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 100/100 for the 2023 performance year (Quality 93.3333), 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

305 E GRANGER AVE
MODESTO, CA 95350

Provider Details

NPI 1508868787
Specialty Nephrology Physician
Credentials MD
Gender Male
NPI Issued 06/01/2005

CMS Quality Score (MIPS)

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

100
Final Score
Avg: 83.1
93.3333
Quality

Reporting: Group practice

Hospital and facility affiliations

Facilities where CHANG JOO, 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.

MODESTO KIDNEY MEDICAL GROUP
MODESTO, 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).

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 CHANG JOO, MD. Source: openpaymentsdata.cms.gov.

Total received

$45

Largest payer

GlaxoSmithKline, LLC.

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 CHANG JOO, MD. To verify CHANG JOO, 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.

1,771
Total Claims
$332K
Total Drug Cost
344
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
4,336
Total Day Supply
127,615
Generic Drug Cost
$114K
Antibiotic Claims
24

Patient Demographics

Average Patient Age
75.4 years
Avg HCC Risk Score
3.08
Gender Split
56% female / 44% male
Age Distribution
<65: 38, 65-74: 100, 75-84: 149, 85+: 57

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Calcitriol
266
Amlodipine Besylate
242
Losartan Potassium
119
Furosemide
98
Hydralazine Hcl
81
Atorvastatin Calcium
77
Lisinopril
56
Prosol
Parenteral Amino Acid 20% No.1
54
Potassium Chloride
49
Metoprolol Tartrate
47

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

Nephrology Physician Overview

How CHANG JOO, 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

CHANG JOO, MD's 1,771 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 JOO.

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

Frequently Asked Questions

What is CHANG JOO, MD's specialty?
CHANG JOO, MD specializes in Nephrology Physician and practices in MODESTO, California. Credentials: MD.
How much does CHANG JOO, MD prescribe under Medicare Part D?
In 2023, CHANG JOO, MD wrote 1,771 Medicare Part D claims totaling $332K in drug costs for 344 beneficiaries.
What is CHANG JOO, MD's Medicare quality score?
CHANG JOO, MD has a CMS MIPS Final Score of 100/100 (Quality: 93.3333). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is CHANG JOO, MD located?
CHANG JOO, MD is located at 305 E GRANGER AVE, MODESTO, CA, 95350. Phone: (209) 526-1606.
What is CHANG JOO, MD's NPI number?
CHANG JOO, MD's National Provider Identifier (NPI) is 1508868787, issued on 06/01/2005.
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 CHANG JOO, MD prescribe most often?
Based on 2023 Medicare Part D data, CHANG JOO, MD's most frequently prescribed drugs include Calcitriol, Amlodipine Besylate, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CHANG JOO, MD accept Medicare?
CHANG JOO, MD appears in CMS Medicare data with 1,771 Part D claims and 344 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CHANG JOO, MD's credentials?
CHANG JOO, MD's NPI is 1508868787 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