Mireille El Hayek, M.D.
NPI 1912139940ActiveIndividual· Internal Medicine, Endocrinology, Diabetes & Metabolism· Saint Louis, MO
Internal Medicine, Endocrinology, Diabetes & Metabolism (M.D.) with Endocrine Associates, LLC, practicing in Saint Louis, Missouri. Their prescriptions cost Medicare Part D more than their services did: $834,231 for 2,036 claims, against $20,233 paid for services in 2024. Novo Nordisk Inc was the largest of 16 companies reporting payments in 2025, $485.64 in all, mostly food and beverage. Lists St Lukes Hospital as a hospital affiliation.
Overview
| NPI | 1912139940 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Aug 8, 2009 |
| Last updated in NPPES | Oct 23, 2023 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Endocrinology, Diabetes & Metabolism Primary | 207RE0101X | 036142174 | IL |
| Internal Medicine, Endocrinology, Diabetes & Metabolism | 207RE0101X | 2015023837 | MO |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Endocrinology (MO) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 110 |
|---|---|
| Services billed | 377 across 9 procedure codes |
| Paid by Medicare | $20,233 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,036 · 4,306 30-day fills |
|---|---|
| Patients | 210 |
| Total drug cost | $834,231 |
| Generic share | 40% of claims |
Education and affiliations
| Graduation year | 2007 |
|---|---|
| Medicare specialty | Endocrinology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Endocrine Associates, LLCChesterfield, MO · 4 clinicians
Hospital affiliation
- St Lukes HospitalChesterfield, MO
Industry payments (Open Payments)
- 2025$485.64 · 25 payments from 16 companies
- 2024$333.16 · 18 payments from 10 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novo Nordisk Inc | $133.70 | 7 |
| Madrigal Pharmaceuticals | $40.39 | 2 |
| Beta Bionics, Inc. | $36.96 | 3 |
| Corcept Therapeutics | $35.45 | 1 |
| Novartis Pharmaceuticals Corporation | $27.55 | 1 |
What the 2025 payments were for
- Food and Beverage$485.64 · 25 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 94 endocrinologists in Saint Louis · All endocrinologists in Missouri