Physician

Louis K Chang, M.D., PH.D.

According to 2025 Medicare claims, Louis Chang, M.D., PH.D. (NPI: 1538295720) practices ophthalmology in the San Francisco-San Mateo-Redwood City, CA market, with the plurality of this provider's patient population coming from San Mateo, CA. This provider's primary affiliated billing organization is NORTHERN CALIFORNIA RETINA VITREOUS ASSOCIATES MEDICAL GROUP, INC. (NPI: 1538275920; TIN: 942906234) and primary practice location at 94401-3859.

Chang's data goes back to 2015 and runs through 2024. For example, in 2024, this provider had 660 traditional Medicare patients, billed 23,664 HCPCS/CPT codes, and received $2,333,151 in Medicare payments. The top billing code was 67028 (Injection of drug into eye). Part D data shows 217 prescription claims across 64 beneficiaries totaling $8,660 in drug costs, led by Prednisolone Acetate (Prednisolone Acetate). Open Payments data shows 3 records totaling $89. You can download detailed data with all billing codes (2015-2024). For more recent data, please contact us.

Over the past 10 years, this provider's Medicare Part B carrier billing has moved from a lower plateau to a higher plateau, from $1,023,790 to $2,333,151. Concurrently, Part D prescription costs did not follow a clear longitudinal pattern. For DME billing, this provider has fewer than 5 years of reported data, so a reliable trend cannot be assigned.

Part B Carrier Billing Trend

Medicare payment trend, with N of patients and claim lines in the table.

Part B Carrier Billing Trend. X-axis: year 2015-2024. Y-axis: Medicare payment, unit: USD. Field: Tot_Mdcr_Pymt_Amt. Source: Medicare Physician & Other Practitioners by Provider.0$1.2M$2.4M2015 Medicare payment: $1,023,790 (USD; Tot_Mdcr_Pymt_Amt)2016 Medicare payment: $973,574 (USD; Tot_Mdcr_Pymt_Amt)2017 Medicare payment: $1,302,463 (USD; Tot_Mdcr_Pymt_Amt)2018 Medicare payment: $1,634,293 (USD; Tot_Mdcr_Pymt_Amt)2019 Medicare payment: $2,193,566 (USD; Tot_Mdcr_Pymt_Amt)2020 Medicare payment: $2,352,351 (USD; Tot_Mdcr_Pymt_Amt)2021 Medicare payment: $2,376,868 (USD; Tot_Mdcr_Pymt_Amt)2022 Medicare payment: $2,018,967 (USD; Tot_Mdcr_Pymt_Amt)2023 Medicare payment: $2,245,636 (USD; Tot_Mdcr_Pymt_Amt)2024 Medicare payment: $2,333,151 (USD; Tot_Mdcr_Pymt_Amt)2015201620172018201920202021202220232024
YearPatientsClm LinesPayment
20155285,964$1,023,790
20165545,985$973,574
20176087,553$1,302,463
20186858,649$1,634,293
201967010,452$2,193,566
202059710,228$2,352,351
20216289,735$2,376,868
20225518,322$2,018,967
202358814,851$2,245,636
202466023,664$2,333,151

Part D Events Trend

Drug cost trend, with N of patients and prescription claims in the table.

Part D Events Trend. X-axis: year 2015-2024. Y-axis: Drug cost, unit: USD. Field: Tot_Drug_Cst. Source: Medicare Part D Prescribers by Provider.0$13K$26K2015 Drug cost: $13,270 (USD; Tot_Drug_Cst)2016 Drug cost: $12,494 (USD; Tot_Drug_Cst)2017 Drug cost: $12,363 (USD; Tot_Drug_Cst)2018 Drug cost: $13,013 (USD; Tot_Drug_Cst)2019 Drug cost: $17,658 (USD; Tot_Drug_Cst)2020 Drug cost: $26,163 (USD; Tot_Drug_Cst)2021 Drug cost: $7,799 (USD; Tot_Drug_Cst)2022 Drug cost: $7,527 (USD; Tot_Drug_Cst)2023 Drug cost: $7,588 (USD; Tot_Drug_Cst)2024 Drug cost: $8,660 (USD; Tot_Drug_Cst)2015201620172018201920202021202220232024
YearPatientsClaimsDrug Cost
201560185$13,270
201668180$12,494
201763189$12,363
201857194$13,013
201966261$17,658
202065241$26,163
202156172$7,799
202251166$7,527
202348165$7,588
202464217$8,660

DME Billing Trend

Medicare payment trend, with N of patients and DME claim records in the table.

No connected DME records

No connected DME records

* / # = suppressed by CMS; 0 = reported zero; N/R = not reported or blank.

Top 5 Part B carrier billing codes in 2024

By total payments.

CodeDescriptionPatientsClm LinesTotal Payment
67028Injection of drug into eye2451,315$116
92014Established patient complete exam of visual system314316$112
92012Established patient problem focused exam of visual system195299$87
99213Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more397991$86
92134Imaging of retina6122,238$41

Top 5 Part D drugs in 2024

By total drug costs.

DrugGenericClaimsTotal Day SupplyTotal Drug Cost
Prednisolone AcetatePrednisolone Acetate632,071$2,435
Ketorolac TromethamineKetorolac Tromethamine341,496$922
Diclofenac SodiumDiclofenac Sodium31998$296
Neomycin-Polymyxin-DexamethNeomycin/Polymyxin B/Dexametha25576$265
Brimonidine TartrateBrimonidine Tartrate16760$134

Top 5 DME services in 2024

No connected or detailed DME service-level records for 2024.

Open Payments Summary in 2024

CategoryDefinitionRecordsTotal Reported AmountTop Related Entity
General PaymentsReported payment or transfer-of-value amount.3$89Genentech USA, Inc.
Research PaymentsReported research-related payment or transfer-of-value amount.0$0N/R
Ownership / Investment InterestsReported value of ownership or investment interests.0$0N/R

FAQ

What Medicare data is available for Louis K. Chang, M.D., PH.D.?

Tedicare shows public-source Medicare data for Louis K. Chang, M.D., PH.D. (NPI 1538295720), including provider identity, specialty, market context, Medicare Part B activity, Part D prescribing, DME records, Open Payments where available, billing organization details, and ACO affiliation signals where available. Profile data covers 2015-2024, with current attribution based on 2025 claims where available.

Does Louis K. Chang, M.D., PH.D. have ACO affiliation data?

No ACO affiliation record is shown in the available Tedicare data for this profile.

What billing organization is linked to Louis K. Chang, M.D., PH.D.?

Louis K. Chang, M.D., PH.D. is linked to NORTHERN CALIFORNIA RETINA VITREOUS ASSOCIATES MEDICAL GROUP, INC. (billing NPI 1538275920) in the available physician profile data.

Does Louis K. Chang, M.D., PH.D. have Open Payments data?

Louis K. Chang, M.D., PH.D. has 3 connected Open Payments records in the available 2024 summary data.

Can I download physician-level Medicare data from Tedicare?

Yes. Tedicare provides sample physician export data and paid custom physician data exports for research, planning, outreach, and market analysis. Exports can include physician profile fields, market and specialty context, billing organization details, ACO affiliation signals where available, and Medicare utilization data.