2026 NPPES data Internal Medicine Physician NPI 1346259595 M.D.
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JYH CHANG, M.D.

Internal Medicine Physician in BALDWIN PARK, 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
6K
Medicare Part D claims · 494 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$261.75
7 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

JYH CHANG, M.D. filed 5,571 Medicare Part D claims in 2023 as a Internal Medicine Physician in BALDWIN PARK, California, prescribing 89% generic.

6K
Part D claims, 2023
89%
generic prescribing
Likely
board-certified (heuristic)

Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.

JYH CHANG, M.D.'s Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

5,571 Top 5% higher than 95% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source CMS Medicare Part D Prescriber Public Use File · 2023

Board certification likely (heuristic — not verified)

JYH CHANG, M.D. 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).

What does the federal data show about JYH CHANG, M.D.?

Quality data not reported

NPI registry status

Active

Issued 08/05/2006

NPI 1346259595

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

5,571 105% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in California

How Internal Medicine Physician compares to other specialties among California providers

California providers

Internal Medicine Physician share within California

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Internal Medicine 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).

JYH CHANG, M.D. appears in the CMS NPPES registry as a Internal Medicine Physician provider holding M.D. credentials at 4318 MAINE AVE STE A, BALDWIN PARK, CA, 91706, with a listed phone of (626) 962-5141. NPI 1346259595 was issued on 08/05/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CHANG 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 5,571 prescription claims written by this provider, covering 494 Medicare beneficiaries and totaling roughly $562K in drug spend, split 11% brand-name and 89% generic by claim count, with an opioid prescribing rate of 0.7%. 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.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

4318 MAINE AVE STE A
BALDWIN PARK, CA 91706

Provider Details

NPI 1346259595
Specialty Internal Medicine Physician
Credentials M.D.
Gender Male
NPI Issued 08/05/2006

Hospital and facility affiliations

Facilities where JYH CHANG, M.D. 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.

JYH C CHANG MD PROFESSIONAL CORPORATION
BALDWIN PARK, 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 JYH CHANG, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$262

Largest payer

Lilly USA, 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 JYH CHANG, M.D.. To verify JYH CHANG, 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 · Typical

JYH CHANG, M.D. — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 5,571 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.

5,571
Total Claims
$562K
Total Drug Cost
494
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
12,061
Total Day Supply
349,285
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$450K
Generic Drug Cost
$108K
Opioid Claims
39 (0.7% rate)
Antibiotic Claims
254

Patient Demographics

Average Patient Age
72.7 years
Avg HCC Risk Score
1.28
Gender Split
54% female / 46% male
Age Distribution
<65: 35, 65-74: 295, 75-84: 109, 85+: 55

Top Prescribed Drugs (Medicare Part D)

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

What JYH CHANG, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Atorvastatin Calcium
413
Metformin Hcl
347
Losartan Potassium
211
Amlodipine Besylate
201
Omeprazole
174
Benazepril Hcl
172
Tamsulosin Hcl
155
Lisinopril
144
Ibuprofen
142
Levothyroxine Sodium
141

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

Internal Medicine Physician Overview

How JYH CHANG, M.D. fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

JYH CHANG, M.D.'s 5,571 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in California

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

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is JYH CHANG, M.D.'s specialty?
JYH CHANG, M.D. specializes in Internal Medicine Physician and practices in BALDWIN PARK, California. Credentials: M.D..
How much does JYH CHANG, M.D. prescribe under Medicare Part D?
In 2023, JYH CHANG, M.D. wrote 5,571 Medicare Part D claims totaling $562K in drug costs for 494 beneficiaries.
Where is JYH CHANG, M.D. located?
JYH CHANG, M.D. is located at 4318 MAINE AVE STE A, BALDWIN PARK, CA, 91706. Phone: (626) 962-5141.
What is JYH CHANG, M.D.'s NPI number?
JYH CHANG, M.D.'s National Provider Identifier (NPI) is 1346259595, issued on 08/05/2006.
Does JYH CHANG, M.D. prescribe more brand-name or generic drugs?
JYH CHANG, M.D.'s prescribing is 11% brand-name and 89% generic drugs by claim count, with $450K in brand drug costs.
Does JYH CHANG, M.D. prescribe opioids?
Yes, JYH CHANG, M.D. had 39 opioid claims in 2023 with an opioid prescribing rate of 0.7%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does JYH CHANG, M.D. prescribe most often?
Based on 2023 Medicare Part D data, JYH CHANG, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Metformin Hcl, Losartan Potassium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JYH CHANG, M.D. accept Medicare?
JYH CHANG, M.D. appears in CMS Medicare data with 5,571 Part D claims and 494 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JYH CHANG, M.D.'s credentials?
JYH CHANG, M.D.'s NPI is 1346259595 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