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Data Sources: Centers for Medicare & Medicaid Services (CMS), Medicare Provider Utilization and Payment Data
Disclaimer: This site is an independent journalism project. Data analysis and editorial content are not affiliated with or endorsed by CMS or any government agency. All spending figures are based on publicly available Medicare payment records.
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ยฉ 2026 OpenMedicare. Independent data journalism. Built by TheDataProject.ai

Methodologyโ€ขDownload Data
  1. Home
  2. Providers
  3. Margaret Chang
๐Ÿ‘๏ธ
MDIndividual

Margaret Chang, M.D.

NPI: 1477504405
Sacramento, CA
10 years of data
Ophthalmology
$47.6M
Total Payments
237
Beneficiaries
281.3K
Services
2.85x
Markup Ratio

Peer Comparison

99th
percentile in specialty
This provider$47.6M
Specialty median$383.7K
Rank #54 of 189 in specialty

๐Ÿ“‹ Key Findings

1Billed $47.6M over 10 years
22.85x markup ratio (above median)
399th percentile in Ophthalmology by payments
4113 services/day โ€” unusually high
57 procedures with >3x markup

This provider averages 113 services per working day

Based on 281.3K total services over 10 years (250 working days/year). Learn about impossible service volumes โ†’

๐Ÿ”Ž Data Analysis

This provider's $47.6M in total Medicare payments ranks in the 99th percentile of Ophthalmology providers nationally.

Averaging 113 services per working day raises questions about billing patterns.

AI-generated analysis based on Medicare payment data.

Annual Medicare Payments

Annual Services Provided

Avg Payment per Service

Markup Ratio Over Time

Submitted Charges vs. Medicare Payments

Average per-service amounts submitted by the provider compared to what Medicare actually paid โ€” the gap represents the markup.

YearAvg SubmittedAvg PaidMarkup RatioGap per ServiceTotal PaymentsServicesBeneficiaries
2014$281.30$162.651.73x$118.65$5.3M32.5K26
2015$463.60$179.342.59x$284.26$5.6M31.4K26
2016$495.33$190.152.60x$305.18$5.1M26.6K24
2017$514.41$193.832.65x$320.58$4.8M24.7K22
2018$512.78$195.502.62x$317.28$4.7M24.0K23
2019$525.45$190.442.76x$335.01$4.5M23.8K21
2020$642.37$205.953.12x$436.42$4.6M22.3K24
2021$810.22$213.893.79x$596.33$4.7M22.0K21
2022$640.11$180.093.55x$460.02$4.0M22.1K24
2023$285.89$83.503.42x$202.39$4.3M51.9K26

Top Procedures (20)

J0178Injection, aflibercept, 1 mgโš  3.1x markup
$21.8M
29.1K services$747.38/svc3.07x markup
J2778Injection, ranibizumab, 0.1 mg
$12.0M
42.7K services$279.88/svc2.58x markup
67028Injection of drug into eyeโš  4.2x markup
$2.7M
29.1K services$93.68/svc4.18x markup
92014Established patient complete exam of visual system
$2.2M
22.7K services$96.93/svc1.98x markup
92235Exam of retinal blood vessels using a special camera after injection of a dye
$1.4M
16.4K services$85.52/svc2.00x markup
92134Imaging of retina
$1.4M
40.8K services$33.93/svc2.45x markup
J2777Injection, faricimab-svoa, 0.1 mg
$1.2M
40.7K services$29.22/svc2.74x markup
92012Established patient problem focused exam of visual system
$961.9K
14.2K services$67.90/svc2.12x markup
92250Photography of the retina
$573.6K
11.7K services$49.13/svc2.07x markup
J7312Injection, dexamethasone, intravitreal implant, 0.1 mg
$503.1K
3.2K services$158.32/svc2.75x markup
J7999Compounded drug, not otherwise classified
$311.0K
4.9K services$64.04/svc1.88x markup
67228Destruction of leaking blood vessels of retina using laser
$310.5K
624 services$497.59/svc2.15x markup
67042Removal of membrane of retina with removal of internal limiting membrane of retinaโš  3.5x markup
$305.9K
306 services$999.54/svc3.51x markup
92004New patient complete exam of visual system
$274.7K
2.3K services$117.05/svc2.14x markup
Q5128Injection, ranibizumab-eqrn (cimerli), biosimilar, 0.1 mgโš  3.1x markup
$266.8K
1.2K services$219.01/svc3.06x markup
67108Repair of detached retina with drainage and removal of eye fluid between lens and retinaโš  4.0x markup
$216.5K
205 services$1.1K/svc3.97x markup
J3590Unclassified biologics
$175.5K
2.6K services$67.53/svc2.40x markup
Q5124Injection, ranibizumab-nuna, biosimilar, (byooviz), 0.1 mg
$172.1K
995 services$172.97/svc2.89x markup
67036Removal of eye fluid (vitreous) between lens and retinaโš  5.1x markup
$131.8K
186 services$708.77/svc5.07x markup
J3490Unclassified drugsโš  4.2x markup
$121.7K
64 services$1.9K/svc4.23x markup
Show detailed table โ–พ
CodeDescriptionServicesPaymentsAvg/ServiceMarkup
J0178Injection, aflibercept, 1 mg29.1K$21.8M$747.383.07x
J2778Injection, ranibizumab, 0.1 mg42.7K$12.0M$279.882.58x
67028Injection of drug into eye29.1K$2.7M$93.684.18x
92014Established patient complete exam of visual system22.7K$2.2M$96.931.98x
92235Exam of retinal blood vessels using a special camera after injection of a dye16.4K$1.4M$85.522.00x
92134Imaging of retina40.8K$1.4M$33.932.45x
J2777Injection, faricimab-svoa, 0.1 mg40.7K$1.2M$29.222.74x
92012Established patient problem focused exam of visual system14.2K$961.9K$67.902.12x
92250Photography of the retina11.7K$573.6K$49.132.07x
J7312Injection, dexamethasone, intravitreal implant, 0.1 mg3.2K$503.1K$158.322.75x
J7999Compounded drug, not otherwise classified4.9K$311.0K$64.041.88x
67228Destruction of leaking blood vessels of retina using laser624$310.5K$497.592.15x
67042Removal of membrane of retina with removal of internal limiting membrane of retina306$305.9K$999.543.51x
92004New patient complete exam of visual system2.3K$274.7K$117.052.14x
Q5128Injection, ranibizumab-eqrn (cimerli), biosimilar, 0.1 mg1.2K$266.8K$219.013.06x
67108Repair of detached retina with drainage and removal of eye fluid between lens and retina205$216.5K$1.1K3.97x
J3590Unclassified biologics2.6K$175.5K$67.532.40x
Q5124Injection, ranibizumab-nuna, biosimilar, (byooviz), 0.1 mg995$172.1K$172.972.89x
67036Removal of eye fluid (vitreous) between lens and retina186$131.8K$708.775.07x
J3490Unclassified drugs64$121.7K$1.9K4.23x

Markup Analysis

Charge-to-Payment Ratio

2.85x

This provider submits charges 2.85 times higher than what Medicare actually pays.

What This Means

A markup ratio of 2.85x means for every $100 Medicare pays, this provider initially charges $285. This is higher than the national average.

Location

Sacramento, CA

Provider Verification

Always verify provider credentials and location before scheduling appointments. This data reflects Medicare payments and may not include all practice locations.

Similar Providers

Other Ophthalmology providers in CA for peer comparison.

Margaret Chang (you)
$47.6M
Nathan Steinle, M.D.
$63.1M
Stephen Couvillion, MD
$47.7M
David Boyer, MD
$47.5M
Alessandro Castellarin, M.D.
$46.9M
Robert Wendel, M.D.
$40.6M
Show detailed table โ–พ
ProviderLocationTotal PaymentsStatus
Nathan Steinle, M.D.Santa Barbara, CA$63.1Mโœ“ Clear
Stephen Couvillion, MDSanta Barbara, CA$47.7Mโœ“ Clear
David Boyer, MDLos Angeles, CA$47.5Mโœ“ Clear
Alessandro Castellarin, M.D.Santa Barbara, CA$46.9Mโœ“ Clear
Robert Wendel, M.D.Sacramento, CA$40.6Mโœ“ Clear

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Data Sources

  • โ€ข Centers for Medicare & Medicaid Services (CMS)
  • โ€ข Medicare Provider Utilization and Payment Data (2014-2023)
  • โ€ข National Plan and Provider Enumeration System (NPPES)

Last Updated: February 2026 (data through 2023, the latest CMS release)

Note: All data is from publicly available Medicare records. OpenMedicare is an independent journalism project not affiliated with CMS.

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