David J. Knysak, MD
NPI 1609876101ActiveIndividual· Allergy & Immunology· Elmhurst, IL
Allergy & Immunology (MD) in Elmhurst, Illinois, trained at Northwestern University Feinberg Medical School (class of 1982). In 2024 Medicare paid $38,133 for 197 patients, and Part D covered 181 of their prescriptions, 73% of them generic. Glaxosmithkline, LLC. was the largest of 8 companies reporting payments in 2025, $644.39 in all, mostly food and beverage.
Overview
| NPI | 1609876101 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jul 26, 2005 |
| Last updated in NPPES | Mar 12, 2018 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Allergy & Immunology Primary | 207K00000X | 036076995 | 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 - Allergy/Immunology (IL) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 197 |
|---|---|
| Services billed | 3,024 across 10 procedure codes |
| Paid by Medicare | $38,133 |
Part D prescriptions in 2024
| Prescriptions (claims) | 181 · 321 30-day fills |
|---|---|
| Patients | 56 |
| Total drug cost | $20,854 |
| Generic share | 73% of claims |
Education and affiliations
| Medical school | Northwestern University Feinberg Medical School |
|---|---|
| Graduation year | 1982 |
| Medicare specialty | Allergy/Immunology |
Medical group
- Oak Brook Allergists SCNaperville, IL · 3 clinicians
Industry payments (Open Payments)
- 2025$644.39 · 29 payments from 8 companies
- 2024$903.57 · 44 payments from 9 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Glaxosmithkline, LLC. | $229.28 | 10 |
| Genzyme Corporation | $151.13 | 6 |
| Astrazeneca Pharmaceuticals LP | $109.34 | 5 |
| Novartis Pharmaceuticals Corporation | $66.13 | 4 |
| Amgen Inc. | $30.00 | 1 |
What the 2025 payments were for
- Food and Beverage$644.39 · 29 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other Allergy & Immunology providers in Elmhurst
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