Healthcare provider profile · identity verified

William Tsai, D.O.

Allopathic & Osteopathic Physicians|Family Medicine · UPLAND, CA · NPI 1285620443

Profile state: payments and partd 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

CMS Open Payments records show William Tsai, D.O. received $817.16 in general payments during 2025 across 36 reported records.

Novo Nordisk Inc accounted for 19.3% of that reported general-payment amount.

The Open Payments records used for this analysis explicitly named 25 associated products.

A separate comparison found the same explicitly named product in public Medicare Part D data: Entresto, Farxiga, Jardiance, Ozempic.

ABBVIE INC. reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported LUMIGAN as an associated drug or biological on 25016 records involving 7645 distinct recipient NPIs. Public Medicare Part D data also shows 11 claims for Lumigan by this doctor in 2024.

Amgen Inc. reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported PROLIA as an associated drug or biological on 20867 records involving 11744 distinct recipient NPIs. Public Medicare Part D data also shows 47 claims for Prolia by this doctor in 2024.

AstraZeneca Pharmaceuticals LP reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported FARXIGA as an associated drug or biological on 106133 records involving 42906 distinct recipient NPIs. Public Medicare Part D data also shows 77 claims for Farxiga by this doctor in 2024.

AstraZeneca Pharmaceuticals LP reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported LOKELMA as an associated drug or biological on 6897 records involving 4326 distinct recipient NPIs. Public Medicare Part D data also shows 23 claims for Lokelma by this doctor in 2024.

Lilly USA, LLC reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported JARDIANCE as an associated drug or biological on 47708 records involving 23833 distinct recipient NPIs. Public Medicare Part D data also shows 158 claims for Jardiance by this doctor in 2024.

Novartis Pharmaceuticals Corporation reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported ENTRESTO as an associated drug or biological on 9346 records involving 6254 distinct recipient NPIs. Public Medicare Part D data also shows 12 claims for Entresto by this doctor in 2024.

Novo Nordisk Inc reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported Ozempic as an associated drug or biological on 261625 records involving 77793 distinct recipient NPIs. Public Medicare Part D data also shows 91 claims for Ozempic by this doctor in 2024.

PFIZER INC. reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported ELIQUIS as an associated drug or biological on 87112 records involving 36032 distinct recipient NPIs. Public Medicare Part D data also shows 66 claims for Eliquis by this doctor in 2024.

PFIZER INC. reported payments to this doctor in 2025. Across the 2025 Open Payments General Payment records loaded for this analysis, that same reporting entity reported PAXLOVID as an associated drug or biological on 24465 records involving 15715 distinct recipient NPIs. Public Medicare Part D data also shows 20 claims for Paxlovid by this doctor in 2024.

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

Payment overview · 2025

General Payments

$817.16

36 reported records · 14 companies

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.

Who paid this doctor?

Companies in 2025 General Payments

Reported companyCanonical companyAmountShareRecordsYear
Novo Nordisk Inc Unresolved — no canonical attribution shown $157.8019.3%62025
Lilly USA, LLC Unresolved — no canonical attribution shown $111.6913.7%52025
Salix Pharmaceuticals, a division of Bausch Health US, LLC Unresolved — no canonical attribution shown $88.7110.9%52025
Amgen Inc. Unresolved — no canonical attribution shown $82.2810.1%42025
Novartis Pharmaceuticals Corporation Unresolved — no canonical attribution shown $69.318.5%32025
AstraZeneca Pharmaceuticals LP Unresolved — no canonical attribution shown $63.547.8%32025
Bayer Healthcare Pharmaceuticals Inc. Unresolved — no canonical attribution shown $55.666.8%22025
Merck Sharp & Dohme LLC Unresolved — no canonical attribution shown $40.034.9%22025
Corcept Therapeutics Unresolved — no canonical attribution shown $36.664.5%12025
Edwards Lifesciences Corporation Unresolved — no canonical attribution shown $27.873.4%12025
PFIZER INC. Unresolved — no canonical attribution shown $26.233.2%12025
Xeris Pharmaceuticals, Inc. Unresolved — no canonical attribution shown $24.693.0%12025
ABBVIE INC. Unresolved — no canonical attribution shown $18.072.2%12025
Exact Sciences Corporation Unresolved — no canonical attribution shown $14.621.8%12025

What were the payments for?

Payment categories

CategoryAmountRecords
Food and Beverage$817.1636

A meal, consulting fee, royalty, and travel payment describe different kinds of reported relationships and should not be interpreted as equivalent.

Analysis 1 · Payment-linked products

Products named in Open Payments records

Reported productTypeReported companyRelated amount*RecordsYear
XIFAXAN
Normalized: xifaxan
Drug Salix Pharmaceuticals, a division of Bausch Health US, LLC $88.71 5 2025
Source payment records
  • 2025-03-13 · Salix Pharmaceuticals, a division of Bausch Health US, LLC · $17.19 · Open Payments source
  • 2025-04-21 · Salix Pharmaceuticals, a division of Bausch Health US, LLC · $15.34 · Open Payments source
  • 2025-05-19 · Salix Pharmaceuticals, a division of Bausch Health US, LLC · $19.94 · Open Payments source
  • 2025-07-14 · Salix Pharmaceuticals, a division of Bausch Health US, LLC · $17.60 · Open Payments source
  • 2025-09-08 · Salix Pharmaceuticals, a division of Bausch Health US, LLC · $18.64 · Open Payments source
OTEZLA
Normalized: otezla
Drug Amgen Inc. $82.28 4 2025
Source payment records
REPATHA
Normalized: repatha
Biological Amgen Inc. $82.28 4 2025
Source payment records
Ozempic
Normalized: ozempic
Drug Novo Nordisk Inc $81.96 3 2025
Source payment records
Wegovy
Normalized: wegovy
Drug Novo Nordisk Inc $75.84 3 2025
Source payment records
LEQVIO
Normalized: leqvio
Drug Novartis Pharmaceuticals Corporation $69.31 3 2025
Source payment records
MOUNJARO
Normalized: mounjaro
Drug Lilly USA, LLC $65.41 3 2025
Source payment records
FARXIGA
Normalized: farxiga
Drug AstraZeneca Pharmaceuticals LP $63.54 3 2025
Source payment records
Kerendia
Normalized: kerendia
Drug Bayer Healthcare Pharmaceuticals Inc. $55.66 2 2025
Source payment records
JARDIANCE
Normalized: jardiance
Drug Lilly USA, LLC $46.28 2 2025
Source payment records
CAPVAXIVE
Normalized: capvaxive
Biological Merck Sharp & Dohme LLC $40.03 2 2025
Source payment records
GARDASIL 9
Normalized: gardasil 9
Biological Merck Sharp & Dohme LLC $40.03 2 2025
Source payment records
M-M-R II
Normalized: m m r ii
Biological Merck Sharp & Dohme LLC $40.03 2 2025
Source payment records
Korlym
Normalized: korlym
Drug Corcept Therapeutics $36.66 1 2025
Source payment records
ENTRESTO
Normalized: entresto
Drug Novartis Pharmaceuticals Corporation $28.22 1 2025
Source payment records
EDWARDS SAPIEN 3 TRANSCATHETER HEART VALVE (THV)
Normalized: edwards sapien 3 transcatheter heart valve thv
Device Edwards Lifesciences Corporation $27.87 1 2025
Source payment records
Rybelsus
Normalized: rybelsus
Drug Novo Nordisk Inc $26.37 1 2025
Source payment records
ABRYSVO
Normalized: abrysvo
Biological PFIZER INC. $26.23 1 2025
Source payment records
COMIRNATY
Normalized: comirnaty
Biological PFIZER INC. $26.23 1 2025
Source payment records
PREVNAR 20
Normalized: prevnar 20
Biological PFIZER INC. $26.23 1 2025
Source payment records
GVOKE HYPOPEN
Normalized: gvoke hypopen
Drug Xeris Pharmaceuticals, Inc. $24.69 1 2025
Source payment records
VAQTA
Normalized: vaqta
Biological Merck Sharp & Dohme LLC $20.53 1 2025
Source payment records
QULIPTA
Normalized: qulipta
Drug ABBVIE INC. $18.07 1 2025
Source payment records
UBRELVY
Normalized: ubrelvy
Drug ABBVIE INC. $18.07 1 2025
Source payment records
The Cologuard Plus Collection Kit
Normalized: the cologuard plus collection kit
Device Exact Sciences Corporation $14.62 1 2025
Source payment records

* Product-associated amounts are non-additive because one payment record may name more than one product.

These products were named on specific Open Payments records. A named product does not show that the payment influenced treatment or prescribing.

Public prescribing for products named in payments

Open Payments productPayment yearPart D brandPart D yearClaimsMatch methodSource
ENTRESTO
entresto
2025 Entresto 2024 12
Beneficiary count suppressed
exact normalized Medicare Part D
FARXIGA
farxiga
2025 Farxiga 2024 77 exact normalized Medicare Part D
JARDIANCE
jardiance
2025 Jardiance 2024 158 exact normalized Medicare Part D
Ozempic
ozempic
2025 Ozempic 2024 91 exact normalized Medicare Part D

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.

Paying companyPayment yearDrug reported by same entityOpen Payments evidencePart DClaimsBeneficiaries
ABBVIE INC.
Exact reporting entity; no affiliate inference
2025 LUMIGAN
open payments reported associated product
CMS Open Payments — General Payments
25016 supporting records · 7645 recipient NPIs · example record 1201352548
Lumigan · 2024
Exact normalized brand match · 1 Part D row
11 suppressed by CMS
Amgen Inc.
Exact reporting entity; no affiliate inference
2025 PROLIA
open payments reported associated product
CMS Open Payments — General Payments
20867 supporting records · 11744 recipient NPIs · example record 1226874448
Prolia · 2024
Exact normalized brand match · 1 Part D row
47 29
AstraZeneca Pharmaceuticals LP
Exact reporting entity; no affiliate inference
2025 FARXIGA
open payments reported associated product
CMS Open Payments — General Payments
106133 supporting records · 42906 recipient NPIs · example record 1206131362
Farxiga · 2024
Exact normalized brand match · 1 Part D row
77 23
AstraZeneca Pharmaceuticals LP
Exact reporting entity; no affiliate inference
2025 LOKELMA
open payments reported associated product
CMS Open Payments — General Payments
6897 supporting records · 4326 recipient NPIs · example record 1206131624
Lokelma · 2024
Exact normalized brand match · 1 Part D row
23 suppressed by CMS
Lilly USA, LLC
Exact reporting entity; no affiliate inference
2025 JARDIANCE
open payments reported associated product
CMS Open Payments — General Payments
47708 supporting records · 23833 recipient NPIs · example record 1186464557
Jardiance · 2024
Exact normalized brand match · 1 Part D row
158 36
Novartis Pharmaceuticals Corporation
Exact reporting entity; no affiliate inference
2025 ENTRESTO
open payments reported associated product
CMS Open Payments — General Payments
9346 supporting records · 6254 recipient NPIs · example record 1200004797
Entresto · 2024
Exact normalized brand match · 1 Part D row
12 suppressed by CMS
Novo Nordisk Inc
Exact reporting entity; no affiliate inference
2025 Ozempic
open payments reported associated product
CMS Open Payments — General Payments
261625 supporting records · 77793 recipient NPIs · example record 1188130076
Ozempic · 2024
Exact normalized brand match · 1 Part D row
91 19
PFIZER INC.
Exact reporting entity; no affiliate inference
2025 ELIQUIS
open payments reported associated product
CMS Open Payments — General Payments
87112 supporting records · 36032 recipient NPIs · example record 1228794063
Eliquis · 2024
Exact normalized brand match · 1 Part D row
66 18
PFIZER INC.
Exact reporting entity; no affiliate inference
2025 PAXLOVID
open payments reported associated product
CMS Open Payments — General Payments
24465 supporting records · 15715 recipient NPIs · example record 1228794432
Paxlovid · 2024
Exact normalized brand match · 1 Part D row
20 20

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 Calcium805203
Amlodipine BesylateAmlodipine Besylate533134
Levothyroxine SodiumLevothyroxine Sodium39178
Losartan PotassiumLosartan Potassium367100
Metformin HclMetformin Hcl28882
Trazodone HclTrazodone Hcl23448
Rosuvastatin CalciumRosuvastatin Calcium22574
Tamsulosin HclTamsulosin Hcl21956
CarvedilolCarvedilol19450
JardianceEmpagliflozin15836
FurosemideFurosemide15533
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen15230
Losartan-HydrochlorothiazideLosartan/Hydrochlorothiazide13231
OmeprazoleOmeprazole12632
Memantine HclMemantine Hcl12418
Benazepril HclBenazepril Hcl11725
Alendronate SodiumAlendronate Sodium11236
Albuterol Sulfate HfaAlbuterol Sulfate10631
CephalexinCephalexin10558
FinasterideFinasteride10425
GabapentinGabapentin10430
Metoprolol SuccinateMetoprolol Succinate10230
FamotidineFamotidine9918
Pantoprazole SodiumPantoprazole Sodium9226
OzempicSemaglutide9119
HydrochlorothiazideHydrochlorothiazide8927
LorazepamLorazepam8920
BaclofenBaclofen8518
LevetiracetamLevetiracetam8513
Donepezil HclDonepezil Hcl8313
Zolpidem TartrateZolpidem Tartrate8012
Potassium ChloridePotassium Chloride7923
Tramadol HclTramadol Hcl7915
FarxigaDapagliflozin Propanediol7723
LactuloseLactulose7621
Fluticasone PropionateFluticasone Propionate7420
LisinoprilLisinopril7421
Escitalopram OxalateEscitalopram Oxalate7316
Divalproex SodiumDivalproex Sodium71suppressed
MirtazapineMirtazapine7114
Quetiapine FumarateQuetiapine Fumarate71suppressed
EzetimibeEzetimibe7019
Montelukast SodiumMontelukast Sodium6815
EliquisApixaban6618
Metoprolol TartrateMetoprolol Tartrate6420
PrednisonePrednisone6315
AzithromycinAzithromycin6139
Triamcinolone AcetonideTriamcinolone Acetonide6123
Hydroxyzine HclHydroxyzine Hcl5719
MyrbetriqMirabegron5512
AlprazolamAlprazolam53suppressed
IbuprofenIbuprofen5016
Clonidine HclClonidine Hcl4812
Ondansetron HclOndansetron Hcl4813
ProliaDenosumab4729
GlipizideGlipizide4416
Diclofenac SodiumDiclofenac Sodium4314
Amlodipine Besylate-BenazeprilAmlodipine Besylate/Benazepril40suppressed
XareltoRivaroxaban40suppressed
Hydralazine HclHydralazine Hcl39suppressed
Fluoxetine HclFluoxetine Hcl38suppressed
TemazepamTemazepam36suppressed
AmoxicillinAmoxicillin3526
Citalopram HbrCitalopram Hydrobromide34suppressed
ClopidogrelClopidogrel Bisulfate3411
Labetalol HclLabetalol Hcl34suppressed
VascepaIcosapent Ethyl34suppressed
Alcohol PadsAlcohol Antiseptic Pads33suppressed
JanuviaSitagliptin Phosphate3312
Lantus SolostarInsulin Glargine,hum.Rec.Anlog32suppressed
LidocaineLidocaine32suppressed
MethimazoleMethimazole31suppressed
Phenytoin Sodium ExtendedPhenytoin Sodium Extended31suppressed
ConstuloseLactulose2912
Isosorbide Mononitrate ErIsosorbide Mononitrate29suppressed
SimvastatinSimvastatin29suppressed
Dicyclomine HclDicyclomine Hcl28suppressed
FenofibrateFenofibrate,micronized28suppressed
HydrocortisoneHydrocortisone2813
Metoclopramide HclMetoclopramide Hcl28suppressed
Sevelamer HclSevelamer Hcl28suppressed
DiazepamDiazepam27suppressed
Toujeo SolostarInsulin Glargine,hum.Rec.Anlog27suppressed
NystatinNystatin2612
Sertraline HclSertraline Hcl26suppressed
AllopurinolAllopurinol25suppressed
ScopolamineScopolamine25suppressed
Buspirone HclBuspirone Hcl24suppressed
RivastigmineRivastigmine Tartrate24suppressed
SpironolactoneSpironolactone24suppressed
Benztropine MesylateBenztropine Mesylate23suppressed
LokelmaSodium Zirconium Cyclosilicate23suppressed
FenofibrateFenofibrate Nanocrystallized22suppressed
NitroglycerinNitroglycerin22suppressed
Toujeo Max SolostarInsulin Glargine,hum.Rec.Anlog22suppressed
ZenpepLipase/Protease/Amylase22suppressed
AtenololAtenolol21suppressed
CarbamazepineCarbamazepine21suppressed
ClonazepamClonazepam21suppressed
JanumetSitagliptin Phos/Metformin Hcl21suppressed
LevofloxacinLevofloxacin2017
Oxycodone-AcetaminophenOxycodone Hcl/Acetaminophen20suppressed
PaxlovidNirmatrelvir/Ritonavir2020
Procto-Med HcHydrocortisone20suppressed
Sumatriptan SuccinateSumatriptan Succinate20suppressed
Amitriptyline HclAmitriptyline Hcl19suppressed
ColchicineColchicine19suppressed
Duloxetine HclDuloxetine Hcl19suppressed
MeloxicamMeloxicam19suppressed
Oxybutynin ChlorideOxybutynin Chloride19suppressed
Tolterodine Tartrate ErTolterodine Tartrate19suppressed
Humulin RInsulin Regular, Human18suppressed
Pravastatin SodiumPravastatin Sodium18suppressed
Propranolol HclPropranolol Hcl18suppressed
RisperidoneRisperidone18suppressed
Amoxicillin-Clavulanate PotassAmoxicillin/Potassium Clav1714
Chlorhexidine GluconateChlorhexidine Gluconate17suppressed
Nano 2nd Gen Pen NeedlePen Needle, Diabetic17suppressed
Warfarin SodiumWarfarin Sodium17suppressed
Azelastine HclAzelastine Hcl16suppressed
Enalapril MaleateEnalapril Maleate16suppressed
LatanoprostLatanoprost16suppressed
Pioglitazone HclPioglitazone Hcl16suppressed
Raloxifene HclRaloxifene Hcl16suppressed
Sildenafil CitrateSildenafil Citrate16suppressed
Valsartan-HydrochlorothiazideValsartan/Hydrochlorothiazide16suppressed
Isosorbide DinitrateIsosorbide Dinitrate15suppressed
Meclizine HclMeclizine Hcl15suppressed
LovastatinLovastatin14suppressed
PermethrinPermethrin14suppressed
Ventolin HfaAlbuterol Sulfate14suppressed
Alcohol SwabsAlcohol Antiseptic Pads13suppressed
Dorzolamide HclDorzolamide Hcl13suppressed
InvokanaCanagliflozin13suppressed
LansoprazoleLansoprazole13suppressed
Lidocaine Hcl ViscousLidocaine Hcl13suppressed
MupirocinMupirocin13suppressed
NikkiEthinyl Estradiol/Drospirenone13suppressed
OxcarbazepineOxcarbazepine13suppressed
Quetiapine Fumarate ErQuetiapine Fumarate13suppressed
Spironolactone-HctzSpironolact/Hydrochlorothiazid13suppressed
TradjentaLinagliptin13suppressed
Bupropion XlBupropion Hcl12suppressed
Cyproheptadine HclCyproheptadine Hcl12suppressed
DapsoneDapsone12suppressed
Doxazosin MesylateDoxazosin Mesylate12suppressed
EntrestoSacubitril/Valsartan12suppressed
Levemir FlexpenInsulin Detemir12suppressed
Nifedipine ErNifedipine12suppressed
OlanzapineOlanzapine12suppressed
RexultiBrexpiprazole12suppressed
RytaryCarbidopa/Levodopa12suppressed
Timolol MaleateTimolol Maleate12suppressed
Acetaminophen-CodeineAcetaminophen With Codeine11suppressed
Basaglar Kwikpen U-100Insulin Glargine,hum.Rec.Anlog11suppressed
EstradiolEstradiol11suppressed
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide11suppressed
LivaloPitavastatin Calcium11suppressed
LoperamideLoperamide Hcl11suppressed
LumiganBimatoprost11suppressed
Ondansetron OdtOndansetron11suppressed
SucralfateSucralfate11suppressed

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 $817.16 · 36 records Novo Nordisk Inc ABRYSVO, CAPVAXIVE, COMIRNATY, EDWARDS SAPIEN 3 TRANSCATHETER HEART VALVE (THV), ENTRESTO, FARXIGA, GARDASIL 9, GVOKE HYPOPEN, JARDIANCE, Kerendia, Korlym, LEQVIO, M-M-R II, MOUNJARO, OTEZLA, Ozempic, PREVNAR 20, QULIPTA, REPATHA, Rybelsus, The Cologuard Plus Collection Kit, UBRELVY, VAQTA, Wegovy, XIFAXAN 9
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