Healthcare provider profile · identity verified

Mark D Shields, MD

Internal Medicine · LAGUNA HILLS, CA · NPI 1366411555

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	453	132
Losartan Potassium	Losartan Potassium	256	76
Amlodipine Besylate	Amlodipine Besylate	251	73
Levothyroxine Sodium	Levothyroxine Sodium	242	73
Pantoprazole Sodium	Pantoprazole Sodium	217	72
Rosuvastatin Calcium	Rosuvastatin Calcium	205	50
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	174	36
Metformin Hcl	Metformin Hcl	170	44
Lisinopril	Lisinopril	162	46
Simvastatin	Simvastatin	151	42
Escitalopram Oxalate	Escitalopram Oxalate	145	38
Hydrochlorothiazide	Hydrochlorothiazide	145	44
Tamsulosin Hcl	Tamsulosin Hcl	141	43
Azithromycin	Azithromycin	139	106
Metoprolol Tartrate	Metoprolol Tartrate	131	36
Sertraline Hcl	Sertraline Hcl	124	35
Omeprazole	Omeprazole	118	33
Potassium Chloride	Potassium Chloride	116	38
Gabapentin	Gabapentin	112	40
Metoprolol Succinate	Metoprolol Succinate	112	32
Methylprednisolone	Methylprednisolone	111	85
Eliquis	Apixaban	107	23
Albuterol Sulfate Hfa	Albuterol Sulfate	103	29
Atenolol	Atenolol	101	30
Trazodone Hcl	Trazodone Hcl	99	26
Furosemide	Furosemide	92	32
Celecoxib	Celecoxib	91	23
Zolpidem Tartrate	Zolpidem Tartrate	85	39
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	79	23
Lorazepam	Lorazepam	76	19
Alprazolam	Alprazolam	73	23
Clopidogrel	Clopidogrel Bisulfate	72	19
Carvedilol	Carvedilol	67	25
Synthroid	Levothyroxine Sodium	66	16
Ciprofloxacin Hcl	Ciprofloxacin Hcl	65	49
Famotidine	Famotidine	65	23
Xarelto	Rivaroxaban	59	13
Alendronate Sodium	Alendronate Sodium	57	16
Prednisone	Prednisone	51	15
Lisinopril-Hydrochlorothiazide	Lisinopril/Hydrochlorothiazide	50	13
Hydralazine Hcl	Hydralazine Hcl	47	12
Pravastatin Sodium	Pravastatin Sodium	43	11
Montelukast Sodium	Montelukast Sodium	42	13
Fluticasone Propionate	Fluticasone Propionate	40	17
Lovastatin	Lovastatin	40	12
Allopurinol	Allopurinol	39	11
Meloxicam	Meloxicam	38	11
Valsartan	Valsartan	38	11
Ezetimibe	Ezetimibe	37	12
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	36	11
Quetiapine Fumarate	Quetiapine Fumarate	36	12
Amlodipine Besylate-Benazepril	Amlodipine Besylate/Benazepril	34	12
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	34	11
Diazepam	Diazepam	31	suppressed
Tramadol Hcl	Tramadol Hcl	31	17
Finasteride	Finasteride	30	11
Pioglitazone Hcl	Pioglitazone Hcl	30	12
Valsartan-Hydrochlorothiazide	Valsartan/Hydrochlorothiazide	30	suppressed
Benazepril Hcl	Benazepril Hcl	29	suppressed
Venlafaxine Hcl Er	Venlafaxine Hcl	29	suppressed
Duloxetine Hcl	Duloxetine Hcl	28	suppressed
Nebivolol Hcl	Nebivolol Hcl	28	suppressed
Paroxetine Hcl	Paroxetine Hcl	28	suppressed
Paxlovid	Nirmatrelvir/Ritonavir	28	28
Sumatriptan Succinate	Sumatriptan Succinate	28	suppressed
Temazepam	Temazepam	28	11
Diltiazem 24hr Er (Cd)	Diltiazem Hcl	27	suppressed
Ipratropium Bromide	Ipratropium Bromide	27	suppressed
Spironolactone	Spironolactone	27	suppressed
Amoxicillin-Clavulanate Potass	Amoxicillin/Potassium Clav	26	16
Januvia	Sitagliptin Phosphate	26	suppressed
Glipizide Er	Glipizide	25	suppressed
Metformin Hcl Er	Metformin Hcl	25	suppressed
Solifenacin Succinate	Solifenacin Succinate	25	suppressed
Pregabalin	Pregabalin	22	suppressed
Citalopram Hbr	Citalopram Hydrobromide	21	suppressed
Fluoxetine Hcl	Fluoxetine Hcl	21	suppressed
Memantine Hcl	Memantine Hcl	21	suppressed
Torsemide	Torsemide	20	suppressed
Diphenoxylate-Atropine	Diphenoxylate Hcl/Atropine	19	suppressed
Ibuprofen	Ibuprofen	19	suppressed
Sildenafil Citrate	Sildenafil Citrate	19	suppressed
Sulfamethoxazole-Trimethoprim	Sulfamethoxazole/Trimethoprim	19	17
Ondansetron Hcl	Ondansetron Hcl	18	11
Bupropion Xl	Bupropion Hcl	17	suppressed
Cefdinir	Cefdinir	17	13
Clonazepam	Clonazepam	17	suppressed
Oxycodone-Acetaminophen	Oxycodone Hcl/Acetaminophen	17	suppressed
Clarithromycin	Clarithromycin	16	15
Fenofibrate	Fenofibrate	16	suppressed
Lansoprazole	Lansoprazole	16	suppressed
Tolterodine Tartrate Er	Tolterodine Tartrate	16	suppressed
Triamcinolone Acetonide	Triamcinolone Acetonide	16	suppressed
Warfarin Sodium	Warfarin Sodium	16	suppressed
Acyclovir	Acyclovir	15	suppressed
Fluticasone-Salmeterol	Fluticasone Propion/Salmeterol	15	suppressed
Folic Acid	Folic Acid	15	suppressed
Isosorbide Mononitrate Er	Isosorbide Mononitrate	15	suppressed
Mirtazapine	Mirtazapine	15	suppressed
Nitroglycerin	Nitroglycerin	15	suppressed
Scopolamine	Scopolamine	15	suppressed
Amiodarone Hcl	Amiodarone Hcl	14	suppressed
Donepezil Hcl	Donepezil Hcl	14	suppressed
Oxycontin	Oxycodone Hcl	14	suppressed
Pramipexole Dihydrochloride	Pramipexole Di-Hcl	14	suppressed
Chlorthalidone	Chlorthalidone	13	suppressed
Doxazosin Mesylate	Doxazosin Mesylate	13	suppressed
Oxybutynin Chloride Er	Oxybutynin Chloride	13	suppressed
Propranolol Hcl Er	Propranolol Hcl	13	suppressed
Alfuzosin Hcl Er	Alfuzosin Hcl	12	suppressed
Diclofenac Sodium	Diclofenac Sodium	12	suppressed
Digoxin	Digoxin	12	suppressed
Dutasteride	Dutasteride	12	suppressed
Azelastine Hcl	Azelastine Hcl	11	suppressed
Ezetimibe-Simvastatin	Ezetimibe/Simvastatin	11	suppressed
Fluocinonide	Fluocinonide	11	suppressed
Hydrocortisone	Hydrocortisone	11	suppressed
Ramipril	Ramipril	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