2026 NPPES data Ophthalmology Physician NPI 1346403961 M.D.
Verify on CMS →

JONATHAN CHANG, M.D.

Ophthalmology Physician in MIDDLETON, Wisconsin. 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
225
Medicare Part D claims · 73 beneficiaries · Ophthalmology Physician avg: 1K
Generic prescribing
60%
generic claims · 40% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

JONATHAN CHANG, M.D. filed 225 Medicare Part D claims in 2023 as a Ophthalmology Physician in MIDDLETON, Wisconsin, prescribing 60% generic.

225
Part D claims, 2023
60%
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.

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

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

225 49th percentile higher than 49% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 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)

JONATHAN 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 JONATHAN CHANG, M.D.?

Quality data not reported

NPI registry status

Active

Issued 07/03/2008

NPI 1346403961

Primary specialty

Ophthalmology Physician

Mid-sized

22,090 US NPIs in this specialty

Medicare Part D claims

225 84% vs specialty avg

2023 prescription claims

Specialty avg: 1,420

Specialty distribution in Wisconsin

How Ophthalmology Physician compares to other specialties among Wisconsin providers

Wisconsin providers

Ophthalmology Physician share within Wisconsin

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

Specialty board-certification context

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

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

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

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

JONATHAN CHANG, M.D. is a Ophthalmology Physician provider practicing in MIDDLETON, Wisconsin, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1346403961. 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.

JONATHAN CHANG, M.D. appears in the CMS NPPES registry as a Ophthalmology Physician provider holding M.D. credentials at 2349 DEMING WAY, MIDDLETON, WI, 53562, with a listed phone of (608) 824-3937. NPI 1346403961 was issued on 07/03/2008. 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 225 prescription claims written by this provider, covering 73 Medicare beneficiaries and totaling roughly $10K in drug spend, split 40% brand-name and 60% 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.

Ophthalmology Physician is a mid-sized specialty nationwide, with 22,090 enrolled providers across 56 states and an average of 1,420 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

2349 DEMING WAY
MIDDLETON, WI 53562

Provider Details

NPI 1346403961
Specialty Ophthalmology Physician
Credentials M.D.
Gender Male
NPI Issued 07/03/2008

Hospital and facility affiliations

Facilities where JONATHAN 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.

UNIVERSITY OF WISCONSIN MEDICAL FOUNDATION INC
MIDDLETON, WI

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Brand vs generic prescribing mix · Above average

JONATHAN CHANG, M.D. — brand share 40.0%
Specialty average (est.)

40% brand-name claims vs 60% generic, on 225 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.

225
Total Claims
$10K
Total Drug Cost
73
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
338
Total Day Supply
8,990
Brand vs Generic
40% brand / 60% generic
Brand Drug Cost
$4K
Generic Drug Cost
$5K

Patient Demographics

Average Patient Age
72.7 years
Avg HCC Risk Score
1.43
Gender Split
48% female / 52% male
Age Distribution
<65: 12, 65-74: 30, 75-84: 20, 85+: 11

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Prednisolone Acetate
66
Latanoprost
25
Dorzolamide-Timolol
Dorzolamide Hcl/Timolol Maleat
17
Brimonidine Tartrate
14
Difluprednate
13
Dorzolamide Hcl
12
Ketorolac Tromethamine
12
Polymyxin B Sul-Trimethoprim
Polymyxin B Sulf/Trimethoprim
11

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

Ophthalmology Physician Overview

How JONATHAN CHANG, M.D. fits within the Ophthalmology Physician landscape nationally.

22,090
Ophthalmology Physician Providers in US
56
States with Ophthalmology Physician
1,420
Avg Claims per Provider

JONATHAN CHANG, M.D.'s 225 claims are below the specialty average of 1,420.

Nearby Ophthalmology Physician Providers in Wisconsin

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

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

Frequently Asked Questions

What is JONATHAN CHANG, M.D.'s specialty?
JONATHAN CHANG, M.D. specializes in Ophthalmology Physician and practices in MIDDLETON, Wisconsin. Credentials: M.D..
How much does JONATHAN CHANG, M.D. prescribe under Medicare Part D?
In 2023, JONATHAN CHANG, M.D. wrote 225 Medicare Part D claims totaling $10K in drug costs for 73 beneficiaries.
Where is JONATHAN CHANG, M.D. located?
JONATHAN CHANG, M.D. is located at 2349 DEMING WAY, MIDDLETON, WI, 53562. Phone: (608) 824-3937.
What is JONATHAN CHANG, M.D.'s NPI number?
JONATHAN CHANG, M.D.'s National Provider Identifier (NPI) is 1346403961, issued on 07/03/2008.
Does JONATHAN CHANG, M.D. prescribe more brand-name or generic drugs?
JONATHAN CHANG, M.D.'s prescribing is 40% brand-name and 60% generic drugs by claim count, with $4K in brand drug costs.
How many Ophthalmology Physician providers are there in the US?
There are 22,090 Ophthalmology Physician providers across 56 states in the US. The average Ophthalmology Physician provider writes 1,420 Medicare Part D claims per year.
What drugs does JONATHAN CHANG, M.D. prescribe most often?
Based on 2023 Medicare Part D data, JONATHAN CHANG, M.D.'s most frequently prescribed drugs include Prednisolone Acetate, Latanoprost, Dorzolamide-Timolol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JONATHAN CHANG, M.D. accept Medicare?
JONATHAN CHANG, M.D. appears in CMS Medicare data with 225 Part D claims and 73 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JONATHAN CHANG, M.D.'s credentials?
JONATHAN CHANG, M.D.'s NPI is 1346403961 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