David Smith Oyer, M.D.
NPI 1134226467ActiveIndividual· Internal Medicine, Endocrinology, Diabetes & Metabolism· Chicago, IL
Internal Medicine, Endocrinology, Diabetes & Metabolism (M.D.) in Chicago, Illinois, trained at Harvard Medical School (class of 1969). Their prescriptions cost Medicare Part D more than their services did: $1,406,798 for 6,152 claims, against $60,229 paid for services in 2024. Novo Nordisk Inc was the largest of 9 companies reporting payments in 2025, $567.06 in all, mostly food and beverage.
Overview
| NPI | 1134226467 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Sep 20, 2006 |
| Last updated in NPPES | Mar 27, 2026 |
| Certified by provider | Mar 27, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Endocrinology, Diabetes & Metabolism Primary | 207RE0101X | 036050957 | IL |
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 (IL) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 225 |
|---|---|
| Services billed | 960 across 20 procedure codes |
| Paid by Medicare | $60,229 |
Part D prescriptions in 2024
| Prescriptions (claims) | 6,152 · 13,977 30-day fills |
|---|---|
| Patients | 304 |
| Total drug cost | $1,406,798 |
| Generic share | 74% of claims |
Education and affiliations
| Medical school | Harvard Medical School |
|---|---|
| Graduation year | 1969 |
| Medicare specialty | Endocrinology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Hospital affiliations
- Bronson Methodist HospitalKalamazoo, MI
- Northshore University Healthsystem - Evanston HospitalEvanston, IL
- Northwestern Lake Forest HospitalLake Forest, IL
- Northwestern Medicine Central Dupage HospitalWinfield, IL
- Northwestern Memorial HospitalChicago, IL
Industry payments (Open Payments)
- 2025$567.06 · 23 payments from 9 companies
- 2024$886.20 · 31 payments from 6 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novo Nordisk Inc | $265.25 | 11 |
| Exact Sciences Corporation | $55.02 | 2 |
| Insulet Corporation | $47.04 | 2 |
| Mannkind Corporation | $42.50 | 1 |
| Bayer Healthcare Pharmaceuticals Inc. | $39.86 | 2 |
What the 2025 payments were for
- Food and Beverage$427.75 · 19 payments
- Education$139.31 · 4 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other endocrinologists in Chicago
- 1003207663
- 1043484561
- 1083976187
- 1093877540
- 1144203647
- 1154408375
- 1194989491
- 1235698143
- 1306375514
- 1316574122
- 1326024134
- 1346299831
All 170 endocrinologists in Chicago · All endocrinologists in Illinois