Healthcare provider profile · identity verified

Michael S. Greenfield, M.D.

Allopathic & Osteopathic Physicians|Internal Medicine|Endocrinology, Diabetes & Metabolism · MOUNTAIN VIEW, CA · NPI 1295873685

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 Michael S. Greenfield, M.D. received $217.07 in general payments during 2025 across 10 reported records.

Amgen Inc. accounted for 34.6% of that reported general-payment amount.

The Open Payments records used for this analysis explicitly named 8 associated products.

A separate comparison found the same explicitly named product in public Medicare Part D data: Prolia.

Amgen 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 PROLIA as an associated drug or biological on 20867 records involving 11744 distinct recipient NPIs. Public Medicare Part D data also shows 16 claims for Prolia by this doctor in 2024.

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

Payment overview · 2025

General Payments

$217.07

10 reported records · 6 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
Amgen Inc. Unresolved — no canonical attribution shown $75.1334.6%32025
Madrigal Pharmaceuticals Unresolved — no canonical attribution shown $46.8021.6%22025
Abbott Laboratories Unresolved — no canonical attribution shown $35.1216.2%22025
Neurocrine BioSciences, Inc. Unresolved — no canonical attribution shown $24.0411.1%12025
Agios Pharmaceuticals, Inc. Unresolved — no canonical attribution shown $19.989.2%12025
Currax Pharmaceuticals LLC Unresolved — no canonical attribution shown $16.007.4%12025

What were the payments for?

Payment categories

CategoryAmountRecords
Food and Beverage$193.039
Education$24.041

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
REPATHA
Normalized: repatha
Biological Amgen Inc. $49.12 2 2025
Source payment records
REZDIFFRA
Normalized: rezdiffra
Drug Madrigal Pharmaceuticals $46.80 2 2025
Source payment records
FREESTYLE LIBRE 3
Normalized: freestyle libre 3
Device Abbott Laboratories $35.12 2 2025
Source payment records
EVENITY
Normalized: evenity
Biological Amgen Inc. $26.01 1 2025
Source payment records
PROLIA
Normalized: prolia
Biological Amgen Inc. $26.01 1 2025
Source payment records
CRENESSITY
Normalized: crenessity
Drug Neurocrine BioSciences, Inc. $24.04 1 2025
Source payment records
PYRUKYND
Normalized: pyrukynd
Drug Agios Pharmaceuticals, Inc. $19.98 1 2025
Source payment records
CONTRAVE
Normalized: contrave
Drug Currax Pharmaceuticals LLC $16.00 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
PROLIA
prolia
2025 Prolia 2024 16
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
Amgen Inc.
Exact reporting entity; no affiliate inference
2025 PROLIA
open payments reported associated product
CMS Open Payments — General Payments
20867 supporting records · 11744 recipient NPIs · example record 1226874448
Prolia · 2024
Exact normalized brand match · 1 Part D row
16 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
Rosuvastatin CalciumRosuvastatin Calcium23167
Levothyroxine SodiumLevothyroxine Sodium18842
Metformin Hcl ErMetformin Hcl15045
Metformin HclMetformin Hcl14740
SynthroidLevothyroxine Sodium13833
JardianceEmpagliflozin13540
Atorvastatin CalciumAtorvastatin Calcium12835
OzempicSemaglutide11822
Losartan PotassiumLosartan Potassium9426
MounjaroTirzepatide67suppressed
EzetimibeEzetimibe5414
HydrochlorothiazideHydrochlorothiazide5315
Nano 2nd Gen Pen NeedlePen Needle, Diabetic4617
Tresiba Flextouch U-100Insulin Degludec4413
FarxigaDapagliflozin Propanediol43suppressed
LisinoprilLisinopril4212
RepaglinideRepaglinide4212
CarvedilolCarvedilol40suppressed
Amlodipine BesylateAmlodipine Besylate3711
SimvastatinSimvastatin37suppressed
LevoxylLevothyroxine Sodium35suppressed
RamiprilRamipril34suppressed
RybelsusSemaglutide32suppressed
JanuviaSitagliptin Phosphate31suppressed
TradjentaLinagliptin29suppressed
GlipizideGlipizide28suppressed
GenotropinSomatropin26suppressed
Alendronate SodiumAlendronate Sodium24suppressed
GlimepirideGlimepiride24suppressed
Lantus SolostarInsulin Glargine,hum.Rec.Anlog23suppressed
IrbesartanIrbesartan22suppressed
Pioglitazone HclPioglitazone Hcl22suppressed
HydrocortisoneHydrocortisone20suppressed
Estradiol (Once Weekly)Estradiol19suppressed
Humalog Kwikpen U-100Insulin Lispro19suppressed
FenofibrateFenofibrate,micronized18suppressed
InvokanaCanagliflozin18suppressed
Liothyronine SodiumLiothyronine Sodium16suppressed
ProliaDenosumab16suppressed
FenofibrateFenofibrate15suppressed
LyumjevInsulin Lispro-Aabc15suppressed
Novolog FlexpenInsulin Aspart13suppressed
FurosemideFurosemide12suppressed
Metoprolol SuccinateMetoprolol Succinate12suppressed
Raloxifene HclRaloxifene Hcl12suppressed

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 $217.07 · 10 records Amgen Inc. CONTRAVE, CRENESSITY, EVENITY, FREESTYLE LIBRE 3, PROLIA, PYRUKYND, REPATHA, REZDIFFRA 1
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