Healthcare provider profile · identity verified

Michael Joseph Greiner, M.D.

Family Practice · FAIRFIELD, IA · NPI 1124133640

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	361	95
Lisinopril	Lisinopril	361	85
Losartan Potassium	Losartan Potassium	325	90
Metoprolol Succinate	Metoprolol Succinate	316	83
Amlodipine Besylate	Amlodipine Besylate	305	83
Levothyroxine Sodium	Levothyroxine Sodium	257	73
Tamsulosin Hcl	Tamsulosin Hcl	248	53
Omeprazole	Omeprazole	209	62
Duloxetine Hcl	Duloxetine Hcl	198	45
Gabapentin	Gabapentin	195	56
Furosemide	Furosemide	184	65
Metformin Hcl	Metformin Hcl	174	53
Hydrochlorothiazide	Hydrochlorothiazide	164	45
Simvastatin	Simvastatin	155	39
Montelukast Sodium	Montelukast Sodium	126	38
Metoprolol Tartrate	Metoprolol Tartrate	115	33
Tramadol Hcl	Tramadol Hcl	96	28
Pravastatin Sodium	Pravastatin Sodium	95	25
Potassium Chloride	Potassium Chloride	92	23
Januvia	Sitagliptin Phosphate	90	16
Rosuvastatin Calcium	Rosuvastatin Calcium	88	23
Albuterol Sulfate Hfa	Albuterol Sulfate	86	35
Lorazepam	Lorazepam	86	16
Clopidogrel	Clopidogrel Bisulfate	82	18
Pantoprazole Sodium	Pantoprazole Sodium	80	24
Allopurinol	Allopurinol	74	24
Zolpidem Tartrate	Zolpidem Tartrate	74	22
Alprazolam	Alprazolam	71	15
Fluoxetine Hcl	Fluoxetine Hcl	68	18
Meloxicam	Meloxicam	68	23
Diclofenac Sodium	Diclofenac Sodium	67	17
Eliquis	Apixaban	66	16
Carvedilol	Carvedilol	65	19
Bupropion Xl	Bupropion Hcl	64	12
Citalopram Hbr	Citalopram Hydrobromide	64	18
Famotidine	Famotidine	64	23
Memantine Hcl	Memantine Hcl	62	12
Pregabalin	Pregabalin	62	15
Alendronate Sodium	Alendronate Sodium	60	16
Finasteride	Finasteride	57	13
Triamcinolone Acetonide	Triamcinolone Acetonide	55	27
Diltiazem 24hr Er (Cd)	Diltiazem Hcl	52	suppressed
Donepezil Hcl	Donepezil Hcl	52	11
Glimepiride	Glimepiride	52	18
Trazodone Hcl	Trazodone Hcl	52	14
Ropinirole Hcl	Ropinirole Hcl	47	13
Atenolol	Atenolol	45	12
Fluticasone Propionate	Fluticasone Propionate	45	15
Metformin Hcl Er	Metformin Hcl	44	11
Buspirone Hcl	Buspirone Hcl	42	suppressed
Lantus Solostar	Insulin Glargine,hum.Rec.Anlog	40	suppressed
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	38	17
Spironolactone	Spironolactone	37	14
Isosorbide Mononitrate Er	Isosorbide Mononitrate	36	12
Doxepin Hcl	Doxepin Hcl	35	suppressed
Sucralfate	Sucralfate	35	suppressed
Baclofen	Baclofen	33	11
Lansoprazole	Lansoprazole	33	suppressed
Escitalopram Oxalate	Escitalopram Oxalate	31	suppressed
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	29	15
Lisinopril-Hydrochlorothiazide	Lisinopril/Hydrochlorothiazide	29	11
Pioglitazone Hcl	Pioglitazone Hcl	29	suppressed
Prednisone	Prednisone	29	14
Warfarin Sodium	Warfarin Sodium	29	11
Azithromycin	Azithromycin	28	25
Ozempic	Semaglutide	28	suppressed
Ultra-Fine Mini Pen Needle	Pen Needle, Diabetic	28	suppressed
Oxybutynin Chloride Er	Oxybutynin Chloride	27	suppressed
Tizanidine Hcl	Tizanidine Hcl	26	suppressed
Midodrine Hcl	Midodrine Hcl	25	suppressed
Naproxen	Naproxen	25	suppressed
Quetiapine Fumarate	Quetiapine Fumarate	25	suppressed
Ventolin Hfa	Albuterol Sulfate	25	suppressed
Diazepam	Diazepam	23	suppressed
Spiriva Handihaler	Tiotropium Bromide	23	suppressed
Linzess	Linaclotide	22	suppressed
Mirtazapine	Mirtazapine	22	suppressed
Oxycodone-Acetaminophen	Oxycodone Hcl/Acetaminophen	22	suppressed
Trelegy Ellipta	Fluticasone/Umeclidin/Vilanter	22	suppressed
Xarelto	Rivaroxaban	22	suppressed
Sertraline Hcl	Sertraline Hcl	21	suppressed
Hydralazine Hcl	Hydralazine Hcl	20	suppressed
Clonazepam	Clonazepam	19	suppressed
Fluticasone-Salmeterol	Fluticasone Propion/Salmeterol	19	suppressed
Glipizide	Glipizide	19	suppressed
Liothyronine Sodium	Liothyronine Sodium	19	suppressed
Prochlorperazine Maleate	Prochlorperazine Maleate	19	suppressed
Estradiol	Estradiol	18	suppressed
Lovastatin	Lovastatin	18	suppressed
Pramipexole Dihydrochloride	Pramipexole Di-Hcl	18	suppressed
Amitriptyline Hcl	Amitriptyline Hcl	17	suppressed
Bumetanide	Bumetanide	17	suppressed
Carbidopa-Levodopa	Carbidopa/Levodopa	17	suppressed
Cefdinir	Cefdinir	17	16
Dutasteride	Dutasteride	17	suppressed
Ketoconazole	Ketoconazole	17	suppressed
Stiolto Respimat	Tiotropium Br/Olodaterol Hcl	17	suppressed
Nystatin	Nystatin	16	suppressed
Sulfamethoxazole-Trimethoprim	Sulfamethoxazole/Trimethoprim	16	11
Irbesartan	Irbesartan	15	suppressed
Topiramate	Topiramate	15	suppressed
Valsartan	Valsartan	15	suppressed
Carbamazepine	Carbamazepine	14	suppressed
Cephalexin	Cephalexin	14	11
Lamotrigine	Lamotrigine	14	suppressed
Nifedipine Er	Nifedipine	14	suppressed
Novolog Flexpen	Insulin Aspart	14	suppressed
Ondansetron Odt	Ondansetron	14	suppressed
Oxycodone Hcl	Oxycodone Hcl	14	suppressed
Rexulti	Brexpiprazole	14	suppressed
Terazosin Hcl	Terazosin Hcl	14	suppressed
Tolterodine Tartrate Er	Tolterodine Tartrate	14	suppressed
Amoxicillin	Amoxicillin	13	suppressed
Basaglar Kwikpen U-100	Insulin Glargine,hum.Rec.Anlog	13	suppressed
Cilostazol	Cilostazol	13	suppressed
Fesoterodine Fumarate Er	Fesoterodine Fumarate	13	suppressed
Fluvoxamine Maleate	Fluvoxamine Maleate	13	suppressed
Haloperidol	Haloperidol	13	suppressed
Levetiracetam	Levetiracetam	13	suppressed
Synthroid	Levothyroxine Sodium	13	suppressed
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	13	suppressed
Amlodipine Besylate-Benazepril	Amlodipine Besylate/Benazepril	12	suppressed
Benazepril Hcl	Benazepril Hcl	12	suppressed
Celecoxib	Celecoxib	12	suppressed
Latanoprost	Latanoprost	12	suppressed
Atomoxetine Hcl	Atomoxetine Hcl	11	suppressed
Azelastine Hcl	Azelastine Hcl	11	suppressed
Dextroamphetamine-Amphet Er	Dextroamphetamine/Amphetamine	11	suppressed
Ezetimibe	Ezetimibe	11	suppressed
Hydroxyzine Pamoate	Hydroxyzine Pamoate	11	suppressed
Lantus	Insulin Glargine,hum.Rec.Anlog	11	suppressed
Morphine Sulfate Er	Morphine Sulfate	11	suppressed
Serevent Diskus	Salmeterol Xinafoate	11	suppressed
Wixela Inhub	Fluticasone Propion/Salmeterol	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