Healthcare provider profile · identity verified

Simon Y. Chang, M.D.

Family Practice · DOWNEY, CA · NPI 1760594097

Profile state: partd only Open Payments: 2025 Medicare Part D: 2024 Last identity check: 2026-08-10 Page data build: 2026-08-12

Verified facts

What the public records show

We did not find matching Open Payments records for this doctor in 2025.

These records do not establish that a payment influenced prescribing or medical care.

Payment overview · 2025

General Payments

We did not find matching Open Payments records for this doctor in the selected program year.

Separate record types

Research & Ownership

Research Payments (direct recipient): not present in the loaded data

Associated Research Funding (for example, named PI): not present in the loaded data

Ownership / Investment: not present in the loaded data

These categories are never added into the General Payments headline. Associated research funding must not be described as money the doctor personally received unless the source record supports that conclusion.

Analysis 1 · Payment-linked products

Products named in Open Payments records

No payment-linked product analysis is available because no matching General Payment records were found for the selected year.

Public prescribing for products named in payments

There is no explicit payment-product set available for a Part D comparison.

The presence of the same drug in both datasets does not show that a payment caused or influenced a prescription.

Analysis 2 · Same-company prescribing overlap

Drugs reported in other payments from the same company that also appear in Medicare Part D

This analysis is independent from products named on this doctor’s individual payment records. A row appears only when the exact Open Payments reporting entity paid this doctor, that same reporting entity reported the drug or biological on at least 10 loaded General Payment records involving at least 2 distinct recipient NPIs, and this doctor has the same non-generic brand in public Part D data. This does not mean the company owns or manufactures the drug.

There is no payer-company set available for this comparison.

These facts do not show that a payment was for the drug, that the company owns or manufactures the drug, or that a payment caused or influenced prescribing.

Public Medicare Part D data

Provider-and-drug rows loaded for 2024

BrandGenericClaimsBeneficiaries
Atorvastatin CalciumAtorvastatin Calcium30992
EliquisApixaban20139
Amlodipine BesylateAmlodipine Besylate16854
Pantoprazole SodiumPantoprazole Sodium13449
Metoprolol TartrateMetoprolol Tartrate11641
Levothyroxine SodiumLevothyroxine Sodium11534
Metformin HclMetformin Hcl9831
FurosemideFurosemide9542
Tamsulosin HclTamsulosin Hcl9436
FamotidineFamotidine9238
GabapentinGabapentin8537
Losartan PotassiumLosartan Potassium7623
OmeprazoleOmeprazole6928
Memantine HclMemantine Hcl6823
Donepezil HclDonepezil Hcl6316
XareltoRivaroxaban61suppressed
Hydralazine HclHydralazine Hcl5616
LisinoprilLisinopril5624
CarvedilolCarvedilol5113
Insulin Lispro Kwikpen U-100Insulin Lispro4721
LevetiracetamLevetiracetam4413
SimvastatinSimvastatin4216
Quetiapine FumarateQuetiapine Fumarate4011
Amiodarone HclAmiodarone Hcl3714
MirtazapineMirtazapine3611
Potassium ChloridePotassium Chloride3516
Alendronate SodiumAlendronate Sodium34suppressed
ClopidogrelClopidogrel Bisulfate3316
LactuloseLactulose3111
Escitalopram OxalateEscitalopram Oxalate30suppressed
PrednisonePrednisone2912
Rosuvastatin CalciumRosuvastatin Calcium29suppressed
Lantus SolostarInsulin Glargine,hum.Rec.Anlog28suppressed
Duloxetine HclDuloxetine Hcl2611
Metoprolol SuccinateMetoprolol Succinate2611
Pravastatin SodiumPravastatin Sodium26suppressed
CreonLipase/Protease/Amylase25suppressed
XifaxanRifaximin25suppressed
Diltiazem 24hr Er (Cd)Diltiazem Hcl23suppressed
Glucagon Emergency KitGlucagon2322
Sodium Chloride0.9 % Sodium Chloride2315
Carbidopa-LevodopaCarbidopa/Levodopa22suppressed
Dicyclomine HclDicyclomine Hcl22suppressed
EnuloseLactulose22suppressed
Ipratropium-AlbuterolIpratropium/Albuterol Sulfate21suppressed
Phenytoin Sodium ExtendedPhenytoin Sodium Extended21suppressed
Albuterol Sulfate HfaAlbuterol Sulfate2013
AtenololAtenolol19suppressed
Buspirone HclBuspirone Hcl19suppressed
DigoxinDigoxin18suppressed
Folic AcidFolic Acid18suppressed
Benazepril HclBenazepril Hcl17suppressed
Trazodone HclTrazodone Hcl17suppressed
Clonidine HclClonidine Hcl1615
FinasterideFinasteride16suppressed
SantylCollagenase Clostridium Hist.16suppressed
AllopurinolAllopurinol15suppressed
LevofloxacinLevofloxacin1512
Midodrine HclMidodrine Hcl15suppressed
RytaryCarbidopa/Levodopa15suppressed
BaclofenBaclofen14suppressed
Ciprofloxacin HclCiprofloxacin Hcl14suppressed
Heparin SodiumHeparin Sodium,porcine14suppressed
Humulin RInsulin Regular, Human14suppressed
Metoclopramide HclMetoclopramide Hcl14suppressed
Sertraline HclSertraline Hcl14suppressed
SpironolactoneSpironolactone14suppressed
SucralfateSucralfate14suppressed
Citalopram HbrCitalopram Hydrobromide13suppressed
FenofibrateFenofibrate Nanocrystallized13suppressed
Humalog Kwikpen U-100Insulin Lispro13suppressed
Insulin Aspart FlexpenInsulin Aspart13suppressed
Mirabegron ErMirabegron13suppressed
Terazosin HclTerazosin Hcl13suppressed
Diltiazem HclDiltiazem Hcl12suppressed
Enoxaparin SodiumEnoxaparin Sodium12suppressed
Fluticasone PropionateFluticasone Propionate12suppressed
HumalogInsulin Lispro12suppressed
Insulin Glargine-YfgnInsulin Glargine-Yfgn12suppressed
Isosorbide DinitrateIsosorbide Dinitrate12suppressed
LatanoprostLatanoprost12suppressed
Montelukast SodiumMontelukast Sodium12suppressed
Ondansetron HclOndansetron Hcl12suppressed
Venlafaxine Hcl ErVenlafaxine Hcl12suppressed
Carbamazepine ErCarbamazepine11suppressed
DapagliflozinDapagliflozin Propanediol11suppressed

Timeline

Payment and prescribing data by year

Open Payments and Medicare Part D may refer to different years. They are shown separately rather than aligned as if they describe the same period.

YearGeneral PaymentsMain payerExplicit productsCompany overlapsPart D coverage
2025
2024 Complete

Questions to ask

Questions you could discuss with your doctor

These are general questions generated from reviewed templates. They are not personalized medical advice.

Sources and limitations

How to read this page

Loaded source releases

DatasetYearPublicationSource
CMS Open Payments — General Payments 2025 2026-06-30 Original source
Medicare Part D Prescribers by Provider and Drug 2024 2026-05-06 Original source
NPPES Data Dissemination V2 current / reference data 2026-08-10 Original source

Methodology version: 2.1

Editorial template version: 2.4

Product contract version: 2.0

Schema version: 0.7.0

Page data build: 2026-08-12T23:34:59.370714+00:00

Publication policy: eligible for indexing after public-launch controls are enabled

Full methodology · Questions & answers · Report a possible error