Healthcare provider profile · identity verified

Ronald Ngayan, MD

Family Practice · CERRITOS, CA · NPI 1134302847

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	478	386
Rosuvastatin Calcium	Rosuvastatin Calcium	284	218
Lisinopril	Lisinopril	261	216
Metformin Hcl	Metformin Hcl	243	191
Amlodipine Besylate	Amlodipine Besylate	232	204
Losartan Potassium	Losartan Potassium	203	159
Glipizide	Glipizide	176	136
Levothyroxine Sodium	Levothyroxine Sodium	145	115
Omeprazole	Omeprazole	142	115
Atenolol	Atenolol	114	98
Hydrochlorothiazide	Hydrochlorothiazide	111	84
Albuterol Sulfate Hfa	Albuterol Sulfate	107	100
Simvastatin	Simvastatin	103	90
Gabapentin	Gabapentin	97	70
Pantoprazole Sodium	Pantoprazole Sodium	93	71
Metoprolol Tartrate	Metoprolol Tartrate	88	72
Alendronate Sodium	Alendronate Sodium	85	75
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	81	23
Lisinopril-Hydrochlorothiazide	Lisinopril/Hydrochlorothiazide	80	63
Jardiance	Empagliflozin	76	53
Ibuprofen	Ibuprofen	75	60
Terazosin Hcl	Terazosin Hcl	75	50
Tamsulosin Hcl	Tamsulosin Hcl	71	58
Bisoprolol Fumarate	Bisoprolol Fumarate	63	40
Metformin Hcl Er	Metformin Hcl	62	47
Potassium Chloride	Potassium Chloride	62	54
Furosemide	Furosemide	61	50
Pradaxa	Dabigatran Etexilate Mesylate	56	41
Ozempic	Semaglutide	54	13
Meloxicam	Meloxicam	52	46
Humulin N	Insulin Nph Human Isophane	47	38
Finasteride	Finasteride	42	33
Trazodone Hcl	Trazodone Hcl	42	37
Nano 2nd Gen Pen Needle	Pen Needle, Diabetic	34	29
Triamcinolone Acetonide	Triamcinolone Acetonide	34	29
Ciclopirox	Ciclopirox	33	24
Allopurinol	Allopurinol	31	21
Sertraline Hcl	Sertraline Hcl	29	24
Acetaminophen-Codeine	Acetaminophen With Codeine	27	suppressed
Hydralazine Hcl	Hydralazine Hcl	27	21
Bupropion Hcl Sr	Bupropion Hcl	24	15
Famotidine	Famotidine	24	20
Prednisone	Prednisone	24	21
Spironolactone	Spironolactone	24	20
Tramadol Hcl	Tramadol Hcl	24	suppressed
Clopidogrel	Clopidogrel Bisulfate	23	19
Duloxetine Hcl	Duloxetine Hcl	23	17
Hydrocortisone	Hydrocortisone	23	18
Doxycycline Monohydrate	Doxycycline Monohydrate	22	21
Adacel Tdap	Diph,pertuss(Acell),tet Vac/Pf	21	21
Lactulose	Lactulose	21	13
Lovastatin	Lovastatin	21	18
Veo Insulin Syringe	Syringe And Needle,insulin,1ml	20	16
Alvesco	Ciclesonide	19	14
Humulin N Kwikpen	Insulin Nph Human Isophane	19	15
Naproxen	Naproxen	19	15
Pioglitazone Hcl	Pioglitazone Hcl	19	15
Carvedilol	Carvedilol	18	17
Fluoxetine Hcl	Fluoxetine Hcl	18	16
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	16	12
Veo Insulin Syringe	Syringe-Needle,insulin,0.5 Ml	16	15
Azelastine Hcl	Azelastine Hcl	15	13
Buspirone Hcl	Buspirone Hcl	15	suppressed
Ezetimibe	Ezetimibe	15	12
Pravastatin Sodium	Pravastatin Sodium	15	14
Ropinirole Hcl	Ropinirole Hcl	15	suppressed
Citalopram Hbr	Citalopram Hydrobromide	14	suppressed
Humulin R	Insulin Regular, Human	14	12
Montelukast Sodium	Montelukast Sodium	14	14
Terbinafine Hcl	Terbinafine Hcl	14	suppressed
Benazepril Hcl	Benazepril Hcl	13	11
Humulin 70/30 Kwikpen	Insulin Nph Hum/Reg Insulin Hm	13	suppressed
Propranolol Hcl	Propranolol Hcl	13	11
Abrysvo	Rsv Vacc, Pref A And Pref B/Pf	12	12
Mupirocin	Mupirocin	12	suppressed
Nortriptyline Hcl	Nortriptyline Hcl	12	suppressed
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	12	suppressed
Veo Insulin Syringe	Syrge-Ndl,ins 0.3 Ml Half Mark	12	11
Wixela Inhub	Fluticasone Propion/Salmeterol	12	11
Amoxicillin-Clavulanate Potass	Amoxicillin/Potassium Clav	11	suppressed
Ciprofloxacin Hcl	Ciprofloxacin Hcl	11	11
Colchicine	Colchicine	11	suppressed
Insulin Glargine-Yfgn	Insulin Glargine-Yfgn	11	suppressed
Lidocaine Hcl Viscous	Lidocaine Hcl	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