Mark K. Isoniemi, M.D.
NPI 1295779239ActiveIndividual· Family Medicine· Wheaton, IL
Family Medicine (M.D.) in Wheaton, Illinois, trained at Ohio State University College of Medicine (class of 1997). Their prescriptions cost Medicare Part D more than their services did: $261,787 for 3,934 claims, against $93,883 paid for services in 2024. Exact Sciences Corporation was the largest of 2 companies reporting payments in 2025, $70.24 in all, mostly food and beverage.
Overview
| NPI | 1295779239 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Jun 16, 2006 |
| Last updated in NPPES | Aug 8, 2023 |
| Certified by provider | Jun 17, 2022 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Family Medicine Primary | 207Q00000X | 036101563 | 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 - Family Practice (IL) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 329 |
|---|---|
| Services billed | 2,310 across 86 procedure codes |
| Paid by Medicare | $93,883 |
Part D prescriptions in 2024
| Prescriptions (claims) | 3,934 · 10,327 30-day fills |
|---|---|
| Patients | 453 |
| Total drug cost | $261,787 |
| Generic share | 92% of claims |
Education and affiliations
| Medical school | Ohio State University College of Medicine |
|---|---|
| Graduation year | 1997 |
| Medicare specialty | Family Practice |
| Telehealth | Offers telehealth |
Medical group
- Dupage Medical Group LtdWinfield, IL · 1,322 clinicians
Hospital affiliation
- Northwestern Medicine Central Dupage HospitalWinfield, IL
Other facilities
- Astra HealthHome health agency · Harwood Heights, IL
Industry payments (Open Payments)
- 2025$70.24 · 3 payments from 2 companies
- 2024$43.27 · 2 payments from 2 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Exact Sciences Corporation | $48.33 | 2 |
| Astrazeneca Pharmaceuticals LP | $21.91 | 1 |
What the 2025 payments were for
- Food and Beverage$70.24 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 58 family medicine physicians in Wheaton · All family medicine physicians in Illinois