2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1114188265 M.D., PH.D.
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DONNY CHANG, M.D., PH.D.

Endocrinology, Diabetes & Metabolism Physician in LEOMINSTER, Massachusetts. 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 · 362 beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
50%
generic claims · 50% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$23.05
1 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: DONNY CHANG, M.D., PH.D. is a Endocrinology, Diabetes & Metabolism Physician ([object Object]) practicing in LEOMINSTER, Massachusetts with a Medicare Part D prescribing footprint of 2K claims across 362 beneficiaries — 50% brand-name prescribing . Industry payments of $23.05 across 1 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: DONNY CHANG, M.D., PH.D. filed 1,620 Medicare Part D claims in 2023 across LEOMINSTER, Massachusetts. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

DONNY CHANG, M.D., PH.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).

DONNY CHANG, M.D., PH.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 06/21/2008

NPI 1114188265

Primary specialty

Endocrinology, Diabetes & Metabolism Physician

Mid-sized

7,852 US NPIs in this specialty

Medicare Part D claims

1,620 39% vs specialty avg

2023 prescription claims

Specialty avg: 2,639

Specialty distribution in Massachusetts

How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Endocrinology, Diabetes & Metabolism Physician share within Massachusetts

1. Endocrinology, Diabetes & Metabolism Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Endocrinology, Diabetes & Metabolism Physician share within Massachusetts

Specialty board-certification context

Estimated specialty board-certified rate — Endocrinology, Diabetes & Metabolism Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Endocrinology, Diabetes & Metabolism Physician ABMS/AOA estimate

Est. board-certified rate (Endocrinology, Diabetes & Metabolism Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Endocrinology, Diabetes & Metabolism 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).

DONNY CHANG, M.D., PH.D. is a Endocrinology, Diabetes & Metabolism Physician provider practicing in LEOMINSTER, Massachusetts, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D., PH.D.. NPI: 1114188265. 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.

DONNY CHANG, M.D., PH.D. appears in the CMS NPPES registry as a Endocrinology, Diabetes & Metabolism Physician provider holding M.D., PH.D. credentials at 225 NEW LANCASTER ROAD, LEOMINSTER, MA, 01453, with a listed phone of (508) 425-5880. NPI 1114188265 was issued on 06/21/2008. 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 1,620 prescription claims written by this provider, covering 362 Medicare beneficiaries and totaling roughly $920K in drug spend, split 50% brand-name and 50% 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.

Endocrinology, Diabetes & Metabolism Physician is a mid-sized specialty nationwide, with 7,852 enrolled providers across 54 states and an average of 2,639 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

225 NEW LANCASTER ROAD
LEOMINSTER, MA 01453

Provider Details

NPI 1114188265
Specialty Endocrinology, Diabetes & Metabolism Physician
Credentials M.D., PH.D.
Gender Male
NPI Issued 06/21/2008

Hospital and facility affiliations

Facilities where DONNY CHANG, M.D., PH.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.

EMERSON PRACTICE ASSOCIATES, INC
CONCORD, MA

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 DONNY CHANG, M.D., PH.D.. Source: openpaymentsdata.cms.gov.

Total received

$23

Largest payer

Medtronic, Inc.

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 — Massachusetts BORIM 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 ~38K Massachusetts medical licensees in 2023 — they are NOT specific to DONNY CHANG, M.D., PH.D.. To verify DONNY CHANG, M.D., PH.D.'s current license status, search the BORIM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

80
Total board actions, Massachusetts 2023
Across 78 cases
2.11
Actions per 1,000 licensees
Massachusetts statewide rate
probation
Most common action type
29 cases

BORIM 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 Massachusetts disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Brand-heavy

DONNY CHANG, M.D., PH.D. — brand share 50.0%
Specialty average (est.)

50% brand-name claims vs 50% generic, on 1,620 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.

1,620
Total Claims
$920K
Total Drug Cost
362
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
3,445
Total Day Supply
102,475
Brand vs Generic
50% brand / 50% generic
Brand Drug Cost
$878K
Generic Drug Cost
$14K

Patient Demographics

Average Patient Age
71.6 years
Avg HCC Risk Score
1.77
Gender Split
59% female / 41% male
Age Distribution
<65: 48, 65-74: 181, 75-84: 108, 85+: 25

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Levothyroxine Sodium
148
Trulicity
Dulaglutide
141
Glipizide
102
Metformin Hcl
102
Alendronate Sodium
81
Metformin Hcl Er
Metformin Hcl
48
Jardiance
Empagliflozin
46
Humalog Kwikpen U-100
Insulin Lispro
42
Farxiga
Dapagliflozin Propanediol
41
Tradjenta
Linagliptin
36

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

Endocrinology, Diabetes & Metabolism Physician Overview

How DONNY CHANG, M.D., PH.D. fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.

7,852
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,639
Avg Claims per Provider

DONNY CHANG, M.D., PH.D.'s 1,620 claims are below the specialty average of 2,639.

Nearby Endocrinology, Diabetes & Metabolism Physician Providers in Massachusetts

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

Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is DONNY CHANG, M.D., PH.D.'s specialty?
DONNY CHANG, M.D., PH.D. specializes in Endocrinology, Diabetes & Metabolism Physician and practices in LEOMINSTER, Massachusetts. Credentials: M.D., PH.D..
How much does DONNY CHANG, M.D., PH.D. prescribe under Medicare Part D?
In 2023, DONNY CHANG, M.D., PH.D. wrote 1,620 Medicare Part D claims totaling $920K in drug costs for 362 beneficiaries.
Where is DONNY CHANG, M.D., PH.D. located?
DONNY CHANG, M.D., PH.D. is located at 225 NEW LANCASTER ROAD, LEOMINSTER, MA, 01453. Phone: (508) 425-5880.
What is DONNY CHANG, M.D., PH.D.'s NPI number?
DONNY CHANG, M.D., PH.D.'s National Provider Identifier (NPI) is 1114188265, issued on 06/21/2008.
Does DONNY CHANG, M.D., PH.D. prescribe more brand-name or generic drugs?
DONNY CHANG, M.D., PH.D.'s prescribing is 50% brand-name and 50% generic drugs by claim count, with $878K in brand drug costs.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US?
There are 7,852 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,639 Medicare Part D claims per year.
What drugs does DONNY CHANG, M.D., PH.D. prescribe most often?
Based on 2023 Medicare Part D data, DONNY CHANG, M.D., PH.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Trulicity, Glipizide. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does DONNY CHANG, M.D., PH.D. accept Medicare?
DONNY CHANG, M.D., PH.D. appears in CMS Medicare data with 1,620 Part D claims and 362 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify DONNY CHANG, M.D., PH.D.'s credentials?
DONNY CHANG, M.D., PH.D.'s NPI is 1114188265 with credentials M.D., PH.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