Healthcare provider profile · identity verified

William Chamberlain

Physician Assistants & Advanced Practice Nursing Providers|Physician Assistant · LOS ANGELES, CA · NPI 1760857247

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 Chamberlain received $241.48 in general payments during 2025 across 14 reported records.

Antares Pharma, Inc. accounted for 34.9% of that reported general-payment amount.

The Open Payments records used for this analysis explicitly named 12 associated products.

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

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 LINZESS as an associated drug or biological on 87954 records involving 21815 distinct recipient NPIs. Public Medicare Part D data also shows 14 claims for Linzess by this doctor in 2024.

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 SYNTHROID as an associated drug or biological on 10655 records involving 4881 distinct recipient NPIs. Public Medicare Part D data also shows 52 claims for Synthroid by this doctor in 2024.

Bayer Healthcare Pharmaceuticals 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 Kerendia as an associated drug or biological on 138674 records involving 48458 distinct recipient NPIs. Public Medicare Part D data also shows 14 claims for Kerendia by this doctor in 2024.

Boehringer Ingelheim Pharmaceuticals, 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 JARDIANCE as an associated drug or biological on 123636 records involving 49438 distinct recipient NPIs. Public Medicare Part D data also shows 28 claims for Jardiance 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 28 claims for Jardiance 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 TRULICITY as an associated drug or biological on 71 records involving 57 distinct recipient NPIs. Public Medicare Part D data also shows 14 claims for Trulicity 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 96 claims for Ozempic 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 Rybelsus as an associated drug or biological on 161257 records involving 55409 distinct recipient NPIs. Public Medicare Part D data also shows 45 claims for Rybelsus by this doctor in 2024.

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

Payment overview · 2025

General Payments

$241.48

14 reported records · 10 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
Antares Pharma, Inc. Unresolved — no canonical attribution shown $84.2134.9%42025
Boehringer Ingelheim Pharmaceuticals, Inc. Unresolved — no canonical attribution shown $27.3411.3%22025
Saluda Medical Americas, Inc. Unresolved — no canonical attribution shown $21.879.1%12025
Lilly USA, LLC Unresolved — no canonical attribution shown $19.468.1%12025
Verity Pharmaceuticals Inc. Unresolved — no canonical attribution shown $16.456.8%12025
ABBVIE INC. Unresolved — no canonical attribution shown $16.046.6%12025
Bayer Healthcare Pharmaceuticals Inc. Unresolved — no canonical attribution shown $14.706.1%12025
AstraZeneca Pharmaceuticals LP Unresolved — no canonical attribution shown $14.396.0%12025
Novo Nordisk Inc Unresolved — no canonical attribution shown $14.055.8%12025
Phathom Pharmaceuticals, Inc. Unresolved — no canonical attribution shown $12.975.4%12025

What were the payments for?

Payment categories

CategoryAmountRecords
Food and Beverage$241.4814

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
XYOSTED
Normalized: xyosted
Drug Antares Pharma, Inc. $84.21 4 2025
Source payment records
JARDIANCE
Normalized: jardiance
Drug Boehringer Ingelheim Pharmaceuticals, Inc. $27.34 2 2025
Source payment records
Evoke
Normalized: evoke
Device Saluda Medical Americas, Inc. $21.87 1 2025
Source payment records
MOUNJARO
Normalized: mounjaro
Drug Lilly USA, LLC $19.46 1 2025
Source payment records
Tlando
Normalized: tlando
Drug Verity Pharmaceuticals Inc. $16.45 1 2025
Source payment records
CREON
Normalized: creon
Drug ABBVIE INC. $16.04 1 2025
Source payment records
LINZESS
Normalized: linzess
Drug ABBVIE INC. $16.04 1 2025
Source payment records
Kerendia
Normalized: kerendia
Drug Bayer Healthcare Pharmaceuticals Inc. $14.70 1 2025
Source payment records
FARXIGA
Normalized: farxiga
Drug AstraZeneca Pharmaceuticals LP $14.39 1 2025
Source payment records
Ozempic
Normalized: ozempic
Drug Novo Nordisk Inc $14.05 1 2025
Source payment records
Rybelsus
Normalized: rybelsus
Drug Novo Nordisk Inc $14.05 1 2025
Source payment records
VOQUEZNA
Normalized: voquezna
Drug Phathom Pharmaceuticals, Inc. $12.97 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
JARDIANCE
jardiance
2025 Jardiance 2024 28
Beneficiary count suppressed
exact normalized Medicare Part D
Kerendia
kerendia
2025 Kerendia 2024 14
Beneficiary count suppressed
exact normalized Medicare Part D
LINZESS
linzess
2025 Linzess 2024 14
Beneficiary count suppressed
exact normalized Medicare Part D
Ozempic
ozempic
2025 Ozempic 2024 96 exact normalized Medicare Part D
Rybelsus
rybelsus
2025 Rybelsus 2024 45
Beneficiary count suppressed
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 LINZESS
open payments reported associated product
CMS Open Payments — General Payments
87954 supporting records · 21815 recipient NPIs · example record 1201352608
Linzess · 2024
Exact normalized brand match · 1 Part D row
14 suppressed by CMS
ABBVIE INC.
Exact reporting entity; no affiliate inference
2025 SYNTHROID
open payments reported associated product
CMS Open Payments — General Payments
10655 supporting records · 4881 recipient NPIs · example record 1201352636
Synthroid · 2024
Exact normalized brand match · 1 Part D row
52 11
Bayer Healthcare Pharmaceuticals Inc.
Exact reporting entity; no affiliate inference
2025 Kerendia
open payments reported associated product
CMS Open Payments — General Payments
138674 supporting records · 48458 recipient NPIs · example record 1225434663
Kerendia · 2024
Exact normalized brand match · 1 Part D row
14 suppressed by CMS
Boehringer Ingelheim Pharmaceuticals, Inc.
Exact reporting entity; no affiliate inference
2025 JARDIANCE
open payments reported associated product
CMS Open Payments — General Payments
123636 supporting records · 49438 recipient NPIs · example record 1221811583
Jardiance · 2024
Exact normalized brand match · 1 Part D row
28 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
28 suppressed by CMS
Lilly USA, LLC
Exact reporting entity; no affiliate inference
2025 TRULICITY
open payments reported associated product
CMS Open Payments — General Payments
71 supporting records · 57 recipient NPIs · example record 1186464601
Trulicity · 2024
Exact normalized brand match · 1 Part D row
14 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
96 18
Novo Nordisk Inc
Exact reporting entity; no affiliate inference
2025 Rybelsus
open payments reported associated product
CMS Open Payments — General Payments
161257 supporting records · 55409 recipient NPIs · example record 1188130076
Rybelsus · 2024
Exact normalized brand match · 1 Part D row
45 suppressed by CMS

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
Levothyroxine SodiumLevothyroxine Sodium548116
Pantoprazole SodiumPantoprazole Sodium483116
Atorvastatin CalciumAtorvastatin Calcium465127
MeloxicamMeloxicam399101
Losartan PotassiumLosartan Potassium386105
PrednisonePrednisone369235
Amlodipine BesylateAmlodipine Besylate35489
LisinoprilLisinopril33086
Albuterol Sulfate HfaAlbuterol Sulfate325129
Metformin HclMetformin Hcl29479
GabapentinGabapentin27165
FurosemideFurosemide24763
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen24648
Potassium ChloridePotassium Chloride24550
Escitalopram OxalateEscitalopram Oxalate24162
Tamsulosin HclTamsulosin Hcl24165
AlprazolamAlprazolam22434
OmeprazoleOmeprazole21842
EstradiolEstradiol20539
AllopurinolAllopurinol20252
AzithromycinAzithromycin200138
HydrochlorothiazideHydrochlorothiazide18047
FluconazoleFluconazole17688
FamotidineFamotidine16444
ClopidogrelClopidogrel Bisulfate15238
Zolpidem TartrateZolpidem Tartrate15222
Amitriptyline HclAmitriptyline Hcl15130
Metoprolol TartrateMetoprolol Tartrate15136
Tramadol HclTramadol Hcl14231
Memantine HclMemantine Hcl14133
Fluticasone PropionateFluticasone Propionate14073
ProgesteroneProgesterone, Micronized12627
Rosuvastatin CalciumRosuvastatin Calcium12532
Metoprolol SuccinateMetoprolol Succinate12233
Pioglitazone HclPioglitazone Hcl12139
SimvastatinSimvastatin11428
Montelukast SodiumMontelukast Sodium10324
EzetimibeEzetimibe9926
Hydroxychloroquine SulfateHydroxychloroquine Sulfate9819
OzempicSemaglutide9618
Trazodone HclTrazodone Hcl9421
Ciprofloxacin HclCiprofloxacin Hcl9164
Losartan-HydrochlorothiazideLosartan/Hydrochlorothiazide9123
BaclofenBaclofen8928
FinasterideFinasteride8724
SpironolactoneSpironolactone8622
Diclofenac SodiumDiclofenac Sodium8527
Sumatriptan SuccinateSumatriptan Succinate8517
Trelegy ElliptaFluticasone/Umeclidin/Vilanter8515
Terbinafine HclTerbinafine Hcl8427
DiazepamDiazepam8216
AtenololAtenolol8126
Ropinirole HclRopinirole Hcl8020
TemazepamTemazepam8020
EliquisApixaban7616
KetoconazoleKetoconazole7631
CarvedilolCarvedilol7328
Testosterone CypionateTestosterone Cypionate7314
Duloxetine HclDuloxetine Hcl6912
GlipizideGlipizide6915
IbuprofenIbuprofen6724
AnastrozoleAnastrozole6520
Acetaminophen-CodeineAcetaminophen With Codeine6120
Triamcinolone AcetonideTriamcinolone Acetonide6132
Ondansetron HclOndansetron Hcl6012
Oxycodone-AcetaminophenOxycodone Hcl/Acetaminophen6013
PregabalinPregabalin6012
ChlorthalidoneChlorthalidone5914
Hydroxyzine HclHydroxyzine Hcl5911
AripiprazoleAripiprazole56suppressed
Doxycycline HyclateDoxycycline Hyclate5444
Quetiapine FumarateQuetiapine Fumarate54suppressed
LorazepamLorazepam5212
Metformin Hcl ErMetformin Hcl52suppressed
SynthroidLevothyroxine Sodium5211
CelecoxibCelecoxib51suppressed
Bydureon BciseExenatide Microspheres50suppressed
Citalopram HbrCitalopram Hydrobromide49suppressed
Donepezil HclDonepezil Hcl49suppressed
Lantus SolostarInsulin Glargine,hum.Rec.Anlog46suppressed
RybelsusSemaglutide45suppressed
Buspirone HclBuspirone Hcl43suppressed
ClonazepamClonazepam43suppressed
Fluoxetine HclFluoxetine Hcl4312
Alendronate SodiumAlendronate Sodium40suppressed
Sertraline HclSertraline Hcl40suppressed
Ventolin HfaAlbuterol Sulfate4016
GlimepirideGlimepiride39suppressed
MetronidazoleMetronidazole3924
Amiodarone HclAmiodarone Hcl38suppressed
Toujeo SolostarInsulin Glargine,hum.Rec.Anlog3712
FenofibrateFenofibrate,micronized36suppressed
ValacyclovirValacyclovir Hcl3614
Oxybutynin Chloride ErOxybutynin Chloride33suppressed
NystatinNystatin3220
Nifedipine ErNifedipine31suppressed
SucralfateSucralfate31suppressed
Cyclobenzaprine HclCyclobenzaprine Hcl3011
Oxybutynin ChlorideOxybutynin Chloride29suppressed
TopiramateTopiramate29suppressed
XareltoRivaroxaban29suppressed
Basaglar Kwikpen U-100Insulin Glargine,hum.Rec.Anlog28suppressed
Clonidine HclClonidine Hcl2813
JardianceEmpagliflozin28suppressed
NaproxenNaproxen28suppressed
Terazosin HclTerazosin Hcl27suppressed
Ondansetron OdtOndansetron2614
Tizanidine HclTizanidine Hcl26suppressed
Benazepril HclBenazepril Hcl25suppressed
Tresiba Flextouch U-200Insulin Degludec25suppressed
LevetiracetamLevetiracetam24suppressed
ValsartanValsartan24suppressed
Vitamin D2Ergocalciferol (Vitamin D2)24suppressed
Bupropion XlBupropion Hcl2311
Propranolol HclPropranolol Hcl23suppressed
Sildenafil CitrateSildenafil Citrate23suppressed
AmoxicillinAmoxicillin2220
LactuloseLactulose22suppressed
LevofloxacinLevofloxacin2219
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide22suppressed
Nano 2nd Gen Pen NeedlePen Needle, Diabetic22suppressed
Xigduo XrDapaglifloz Propaned/Metformin22suppressed
MovantikNaloxegol Oxalate21suppressed
NitrofurantoinNitrofurantoin Macrocrystal21suppressed
CephalexinCephalexin20suppressed
RexultiBrexpiprazole20suppressed
Varenicline TartrateVarenicline Tartrate20suppressed
Anoro ElliptaUmeclidinium Brm/Vilanterol Tr19suppressed
Bupropion Hcl SrBupropion Hcl19suppressed
Fluticasone-SalmeterolFluticasone Propion/Salmeterol19suppressed
Hydralazine HclHydralazine Hcl19suppressed
JanuviaSitagliptin Phosphate19suppressed
MethotrexateMethotrexate Sodium19suppressed
FenofibrateFenofibrate18suppressed
RizatriptanRizatriptan Benzoate18suppressed
Dexlansoprazole DrDexlansoprazole17suppressed
GlyxambiEmpagliflozin/Linagliptin17suppressed
Nitrofurantoin Mono-MacroNitrofurantoin Monohyd/M-Cryst1715
Breo ElliptaFluticasone/Vilanterol16suppressed
DutasterideDutasteride16suppressed
NitroglycerinNitroglycerin16suppressed
NystopNystatin16suppressed
Promethazine HclPromethazine Hcl16suppressed
Tamoxifen CitrateTamoxifen Citrate16suppressed
LoperamideLoperamide Hcl15suppressed
MetaxaloneMetaxalone15suppressed
MupirocinMupirocin15suppressed
Doxazosin MesylateDoxazosin Mesylate14suppressed
KerendiaFinerenone14suppressed
LinzessLinaclotide14suppressed
NyamycNystatin14suppressed
Triamterene-HydrochlorothiazidTriamterene/Hydrochlorothiazid14suppressed
TrulicityDulaglutide14suppressed
Venlafaxine Hcl ErVenlafaxine Hcl14suppressed
Verapamil ErVerapamil Hcl14suppressed
Bupropion HclBupropion Hcl13suppressed
Clotrimazole-BetamethasoneClotrimazole/Betamethasone Dip13suppressed
FenofibrateFenofibrate Nanocrystallized13suppressed
Meclizine HclMeclizine Hcl13suppressed
Paroxetine HclParoxetine Hcl13suppressed
PrimidonePrimidone13suppressed
CalcitriolCalcitriol12suppressed
Droplet Pen NeedlePen Needle, Diabetic12suppressed
EszopicloneEszopiclone12suppressed
Lurasidone HclLurasidone Hcl12suppressed
Oxycodone HclOxycodone Hcl12suppressed
RisperidoneRisperidone12suppressed
Amlodipine-ValsartanAmlodipine Besylate/Valsartan11suppressed
CarisoprodolCarisoprodol11suppressed
ErythromycinErythromycin Base11suppressed
Glipizide ErGlipizide11suppressed
LatanoprostLatanoprost11suppressed
Methenamine HippurateMethenamine Hippurate11suppressed
Valsartan-HydrochlorothiazideValsartan/Hydrochlorothiazide11suppressed
Ziprasidone HclZiprasidone Hcl11suppressed

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 $241.48 · 14 records Antares Pharma, Inc. CREON, Evoke, FARXIGA, JARDIANCE, Kerendia, LINZESS, MOUNJARO, Ozempic, Rybelsus, Tlando, VOQUEZNA, XYOSTED 8
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