Daniel J. Grzegorek, D.O.
NPI 1487651337ActiveIndividual· Internal Medicine· Willowbrook, IL
Internal Medicine (D.O.) in Willowbrook, Illinois, trained at Chicago College of Osteopathy (class of 1992). Their prescriptions cost Medicare Part D more than their services did: $621,802 for 11,602 claims, against $273,964 paid for services in 2024.
Overview
| NPI | 1487651337 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | No |
| NPI issued | Jul 7, 2005 |
| Last updated in NPPES | Aug 8, 2023 |
| Certified by provider | Aug 8, 2023 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | 036-089211 | IL |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Internal Medicine (IL) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 641 |
|---|---|
| Services billed | 6,210 across 87 procedure codes |
| Paid by Medicare | $273,964 |
Part D prescriptions in 2024
| Prescriptions (claims) | 11,602 · 23,394 30-day fills |
|---|---|
| Patients | 821 |
| Total drug cost | $621,802 |
| Generic share | 89% of claims |
Education and affiliations
| Medical school | Chicago College of Osteopathy |
|---|---|
| Graduation year | 1992 |
| Medicare specialty | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Dupage Medical Group LtdWinfield, IL · 1,322 clinicians
Hospital affiliation
- Uchicago Medicine Adventhealth HinsdaleHinsdale, IL
Other facilities
- Advocate Home Health Care ServHome health agency · Oakbrook, IL
- Residential Home HealthHome health agency · Lisle, IL
- Uchicago Medicine Adventhealth Home CareHome health agency · La Grange, IL
- Angels Grace HospiceHospice · Bolingbrook, IL
- Residential HospiceHospice · Northbrook, IL
- Residential Hospice LLCHospice · Lisle, IL
- Burgess Square Healthcare CtrNursing home · Westmont, IL
Industry payments (Open Payments)
None reported for 2025 or 2024.
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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