Healthcare provider profile · identity verified

David S Chang, DO

Family Practice · SILVERDALE, WA · NPI 1437465424

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

Brand	Generic	Claims	Beneficiaries
Atorvastatin Calcium	Atorvastatin Calcium	552	218
Losartan Potassium	Losartan Potassium	366	131
Levothyroxine Sodium	Levothyroxine Sodium	302	107
Amlodipine Besylate	Amlodipine Besylate	276	105
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	255	61
Lisinopril	Lisinopril	228	90
Albuterol Sulfate Hfa	Albuterol Sulfate	205	113
Ibuprofen	Ibuprofen	203	78
Metoprolol Tartrate	Metoprolol Tartrate	183	69
Fluticasone Propionate	Fluticasone Propionate	171	66
Trazodone Hcl	Trazodone Hcl	167	60
Duloxetine Hcl	Duloxetine Hcl	157	59
Simvastatin	Simvastatin	157	58
Furosemide	Furosemide	156	59
Omeprazole	Omeprazole	147	57
Atenolol	Atenolol	143	58
Hydrochlorothiazide	Hydrochlorothiazide	132	53
Gabapentin	Gabapentin	131	56
Pantoprazole Sodium	Pantoprazole Sodium	130	43
Famotidine	Famotidine	129	47
Tamsulosin Hcl	Tamsulosin Hcl	124	49
Metformin Hcl	Metformin Hcl	99	40
Glipizide	Glipizide	96	32
Lisinopril-Hydrochlorothiazide	Lisinopril/Hydrochlorothiazide	96	38
Potassium Chloride	Potassium Chloride	92	43
Allopurinol	Allopurinol	85	30
Fluoxetine Hcl	Fluoxetine Hcl	84	23
Hydroxyzine Hcl	Hydroxyzine Hcl	82	20
Alvesco	Ciclesonide	80	38
Metoprolol Succinate	Metoprolol Succinate	78	32
Rosuvastatin Calcium	Rosuvastatin Calcium	77	32
Metformin Hcl Er	Metformin Hcl	76	33
Alendronate Sodium	Alendronate Sodium	74	29
Tramadol Hcl	Tramadol Hcl	73	20
Terazosin Hcl	Terazosin Hcl	70	21
Doxycycline Monohydrate	Doxycycline Monohydrate	66	45
Sertraline Hcl	Sertraline Hcl	64	29
Meloxicam	Meloxicam	63	27
Ropinirole Hcl	Ropinirole Hcl	62	16
Wixela Inhub	Fluticasone Propion/Salmeterol	61	27
Pradaxa	Dabigatran Etexilate Mesylate	60	21
Triamcinolone Acetonide	Triamcinolone Acetonide	60	35
Prednisone	Prednisone	59	48
Lovastatin	Lovastatin	58	22
Jardiance	Empagliflozin	57	24
Ondansetron Odt	Ondansetron	55	24
Warfarin Sodium	Warfarin Sodium	54	17
Montelukast Sodium	Montelukast Sodium	50	20
Nitrofurantoin Mono-Macro	Nitrofurantoin Monohyd/M-Cryst	50	39
Spiriva Respimat	Tiotropium Bromide	50	18
Lorazepam	Lorazepam	49	25
Clopidogrel	Clopidogrel Bisulfate	48	16
Spironolactone	Spironolactone	48	19
Alprazolam	Alprazolam	45	13
Lactulose	Lactulose	45	12
Trospium Chloride	Trospium Chloride	45	14
Diltiazem 24hr Er (Cd)	Diltiazem Hcl	44	13
Acyclovir	Acyclovir	43	15
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	42	21
Propranolol Hcl	Propranolol Hcl	42	14
Azelastine Hcl	Azelastine Hcl	40	14
Donepezil Hcl	Donepezil Hcl	40	13
Paxlovid	Nirmatrelvir/Ritonavir	39	39
Zolpidem Tartrate	Zolpidem Tartrate	39	suppressed
Mirtazapine	Mirtazapine	37	13
Carvedilol	Carvedilol	35	14
Venlafaxine Hcl Er	Venlafaxine Hcl	35	11
Oxycodone-Acetaminophen	Oxycodone Hcl/Acetaminophen	34	15
Sumatriptan Succinate	Sumatriptan Succinate	34	suppressed
Chlorthalidone	Chlorthalidone	31	14
Citalopram Hbr	Citalopram Hydrobromide	31	suppressed
Amoxicillin	Amoxicillin	30	27
Buspirone Hcl	Buspirone Hcl	30	14
Fenofibrate	Fenofibrate	30	suppressed
Humulin N	Insulin Nph Human Isophane	30	suppressed
Naratriptan Hcl	Naratriptan Hcl	28	suppressed
Nortriptyline Hcl	Nortriptyline Hcl	28	15
Veo Insulin Syringe	Syringe-Needle,insulin,0.5 Ml	28	14
Bupropion Hcl Sr	Bupropion Hcl	27	12
Bupropion Xl	Bupropion Hcl	27	suppressed
Cefadroxil	Cefadroxil	27	24
Clonidine Hcl	Clonidine Hcl	27	suppressed
Azithromycin	Azithromycin	26	26
Naproxen	Naproxen	26	suppressed
Pregabalin	Pregabalin	26	suppressed
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	26	suppressed
Oxycodone Hcl	Oxycodone Hcl	25	suppressed
Topiramate	Topiramate	25	suppressed
Clobetasol Propionate	Clobetasol Propionate	24	14
Clonazepam	Clonazepam	24	suppressed
Nystatin	Nystatin	24	18
Paroxetine Hcl	Paroxetine Hcl	24	12
Finasteride	Finasteride	23	suppressed
Breyna	Budesonide/Formoterol Fumarate	22	suppressed
Insulin Glargine-Yfgn	Insulin Glargine-Yfgn	22	suppressed
Tizanidine Hcl	Tizanidine Hcl	22	14
Ciprofloxacin Hcl	Ciprofloxacin Hcl	21	13
Ezetimibe	Ezetimibe	20	suppressed
Hydrocortisone	Hydrocortisone	20	11
Levetiracetam	Levetiracetam	20	suppressed
Amoxicillin-Clavulanate Potass	Amoxicillin/Potassium Clav	19	19
Latanoprost	Latanoprost	19	suppressed
Naloxone Hcl	Naloxone Hcl	18	13
Rizatriptan	Rizatriptan Benzoate	18	suppressed
Dicyclomine Hcl	Dicyclomine Hcl	17	suppressed
Ondansetron Hcl	Ondansetron Hcl	17	suppressed
Pravastatin Sodium	Pravastatin Sodium	17	suppressed
Venlafaxine Hcl	Venlafaxine Hcl	17	suppressed
Cephalexin	Cephalexin	16	16
Methocarbamol	Methocarbamol	16	suppressed
Celecoxib	Celecoxib	15	suppressed
Fluconazole	Fluconazole	15	12
Pramipexole Dihydrochloride	Pramipexole Di-Hcl	15	suppressed
Sulfamethoxazole-Trimethoprim	Sulfamethoxazole/Trimethoprim	15	14
Cefpodoxime Proxetil	Cefpodoxime Proxetil	14	12
Colchicine	Colchicine	14	suppressed
Ketoconazole	Ketoconazole	14	suppressed
Nitroglycerin	Nitroglycerin	14	11
Adacel Tdap	Diph,pertuss(Acell),tet Vac/Pf	13	13
Baclofen	Baclofen	13	suppressed
Escitalopram Oxalate	Escitalopram Oxalate	13	suppressed
Esomeprazole Magnesium	Esomeprazole Magnesium	13	suppressed
Ozempic	Semaglutide	13	suppressed
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	12	suppressed
Humalog Kwikpen U-100	Insulin Lispro	12	suppressed
Oxybutynin Chloride Er	Oxybutynin Chloride	12	suppressed
Pioglitazone Hcl	Pioglitazone Hcl	12	suppressed
Stiolto Respimat	Tiotropium Br/Olodaterol Hcl	12	suppressed
Alclometasone Dipropionate	Alclometasone Dipropionate	11	suppressed
Brilinta	Ticagrelor	11	suppressed
Diltiazem 12hr Er	Diltiazem Hcl	11	suppressed
Epinephrine	Epinephrine	11	suppressed
Estradiol	Estradiol	11	suppressed
Glimepiride	Glimepiride	11	suppressed
Humulin 70-30	Insulin Nph Hum/Reg Insulin Hm	11	suppressed
Humulin R	Insulin Regular, Human	11	suppressed
Temazepam	Temazepam	11	suppressed

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.

Year	General Payments	Main payer	Explicit products	Company overlaps	Part D coverage
2025	—	—	—	—	—
2024	—	—	—	—	Complete

Questions to ask

Questions you could discuss with your doctor

Are there reasonable alternatives I should understand when we discuss treatment options?
How should I interpret the industry-payment records shown here in the context of my care?

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

Sources and limitations

How to read this page

Payment and Medicare prescribing data can cover different years; every comparison shows both years explicitly.
Part D does not represent a doctor’s entire practice; it excludes many patients and is subject to CMS public-release thresholds.
Company–drug relationships must have an auditable source, a precise relationship type, and a valid evidence period. Unresolved mappings are not published.
Generic drug claims are not attributed to a specific manufacturer without manufacturer-level evidence.
When a source extract is incomplete, missing rows are never treated as proof of no payments or no prescriptions.

Loaded source releases

Dataset	Year	Publication	Source
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