2026 NPPES data Surgery of the Hand (Surgery) Physician NPI 1083781835 MD
Verify on CMS →

WALTER CHANG, MD

Surgery of the Hand (Surgery) Physician in FONTANA, 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
52
Medicare Part D claims · 36 beneficiaries · Surgery of the Hand (Surgery) Physician avg: 175
Industry payments
$477.52
2 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

WALTER CHANG, MD filed 52 Medicare Part D claims in 2023 as a Surgery of the Hand (Surgery) Physician in FONTANA, California.

52
Part D claims, 2023
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.

WALTER CHANG, MD's Medicare Part D volume vs every U.S. prescriber

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

52 0th percentile higher than 0% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. 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)

WALTER CHANG, MD 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 WALTER CHANG, MD?

Quality data not reported

NPI registry status

Active

Issued 11/29/2006

NPI 1083781835

Primary specialty

Surgery of the Hand (Surgery) Physician

Rare

394 US NPIs in this specialty

Medicare Part D claims

52 70% vs specialty avg

2023 prescription claims

Specialty avg: 175

Specialty distribution in California

How Surgery of the Hand (Surgery) Physician compares to other specialties among California providers

California providers

Surgery of the Hand (Surgery) Physician share within California

1. Surgery of the Hand (Surgery) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Surgery of the Hand (Surgery) Physician share within California

Specialty board-certification context

Estimated specialty board-certified rate — Surgery of the Hand (Surgery) Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Surgery of the Hand (Surgery) Physician ABMS/AOA estimate

Est. board-certified rate (Surgery of the Hand (Surgery) Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Surgery of the Hand (Surgery) 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).

WALTER CHANG, MD is a Surgery of the Hand (Surgery) Physician provider practicing in FONTANA, California, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1083781835. 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.

WALTER CHANG, MD appears in the CMS NPPES registry as a Surgery of the Hand (Surgery) Physician provider holding MD credentials at 9961 SIERRA AVE, FONTANA, CA, 92335, with a listed phone of (909) 427-3910. NPI 1083781835 was issued on 11/29/2006. 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 52 prescription claims written by this provider, covering 36 Medicare beneficiaries and totaling roughly $5K in drug spend, with an opioid prescribing rate of 38.5%. 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.

Surgery of the Hand (Surgery) Physician is a narrow specialty nationwide, with 394 enrolled providers across 44 states and an average of 175 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

9961 SIERRA AVE
FONTANA, CA 92335

Provider Details

NPI 1083781835
Specialty Surgery of the Hand (Surgery) Physician
Credentials MD
Gender Male
NPI Issued 11/29/2006

Hospital and facility affiliations

Facilities where WALTER CHANG, 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.

SOUTHERN CALIFORNIA PERMANENTE MEDICAL GROUP
ONTARIO, 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 WALTER CHANG, MD. Source: openpaymentsdata.cms.gov.

Total received

$478

Largest payer

KLS-Martin L.P.

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 WALTER CHANG, MD. To verify WALTER CHANG, 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.

52
Total Claims
$5K
Total Drug Cost
36
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
86
Total Day Supply
1,903
Generic Drug Cost
$513
Opioid Claims
20 (38.5% rate)

Patient Demographics

Average Patient Age
70.3 years
Avg HCC Risk Score
1.35
Gender Split
50% female / 50% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
16

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

Surgery of the Hand (Surgery) Physician Overview

How WALTER CHANG, MD fits within the Surgery of the Hand (Surgery) Physician landscape nationally.

394
Surgery of the Hand (Surgery) Physician Providers in US
44
States with Surgery of the Hand (Surgery) Physician
175
Avg Claims per Provider

WALTER CHANG, MD's 52 claims are below the specialty average of 175.

Nearby Surgery of the Hand (Surgery) Physician Providers in California

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

Compare Surgery of the Hand (Surgery) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is WALTER CHANG, MD's specialty?
WALTER CHANG, MD specializes in Surgery of the Hand (Surgery) Physician and practices in FONTANA, California. Credentials: MD.
How much does WALTER CHANG, MD prescribe under Medicare Part D?
In 2023, WALTER CHANG, MD wrote 52 Medicare Part D claims totaling $5K in drug costs for 36 beneficiaries.
Where is WALTER CHANG, MD located?
WALTER CHANG, MD is located at 9961 SIERRA AVE, FONTANA, CA, 92335. Phone: (909) 427-3910.
What is WALTER CHANG, MD's NPI number?
WALTER CHANG, MD's National Provider Identifier (NPI) is 1083781835, issued on 11/29/2006.
Does WALTER CHANG, MD prescribe opioids?
Yes, WALTER CHANG, MD had 20 opioid claims in 2023 with an opioid prescribing rate of 38.5%.
How many Surgery of the Hand (Surgery) Physician providers are there in the US?
There are 394 Surgery of the Hand (Surgery) Physician providers across 44 states in the US. The average Surgery of the Hand (Surgery) Physician provider writes 175 Medicare Part D claims per year.
What drugs does WALTER CHANG, MD prescribe most often?
Based on 2023 Medicare Part D data, WALTER CHANG, MD's most frequently prescribed drugs include Hydrocodone-Acetaminophen. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does WALTER CHANG, MD accept Medicare?
WALTER CHANG, MD appears in CMS Medicare data with 52 Part D claims and 36 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify WALTER CHANG, MD's credentials?
WALTER CHANG, MD's NPI is 1083781835 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.
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