Marissa Lorena Walczak, FNP-BC
NPI 1871291906ActiveIndividual· Nurse Practitioner, Family· Rice Lake, WI
Nurse Practitioner, Family (FNP-BC) with McHs Hospitals Inc and 2 other groups, practicing in Rice Lake, Wisconsin. Their prescriptions cost Medicare Part D more than their services did: $91,758 for 572 claims, against $2,280 paid for services in 2024. Lists Marshfield Medical Center - Eau Claire and 2 other hospitals as hospital affiliations.
Overview
| NPI | 1871291906 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | FNP-BC |
| Sole proprietor | No |
| NPI issued | Feb 17, 2023 |
| Last updated in NPPES | Sep 2, 2026 |
| Certified by provider | Sep 2, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Nurse Practitioner, Family Primary | 363LF0000X | 13864-33 | WI |
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 - Nurse Practitioner (WI) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 16 |
|---|---|
| Services billed | 21 across 5 procedure codes |
| Paid by Medicare | $2,280 |
Part D prescriptions in 2024
| Prescriptions (claims) | 572 · 1,114 30-day fills |
|---|---|
| Patients | 121 |
| Total drug cost | $91,758 |
| Generic share | 91% of claims |
Education and affiliations
| Graduation year | 2022 |
|---|---|
| Medicare specialty | Nurse Practitioner |
Medical groups
- McHs Hospitals IncMarshfield, WI · 1,197 clinicians
- Lakeview Medical Center Inc of Rice LakeRice Lake, WI · 168 clinicians
- Oakleaf Clinics IncRice Lake, WI · 103 clinicians
Hospital affiliations
- Marshfield Medical Center - Eau ClaireEau Claire, WI
- Marshfield Medical Center - MinocquaMinocqua, WI
- Marshfield Medical Center - Rice LakeRice Lake, WI
Industry payments (Open Payments)
None reported for 2025 or 2024.
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other Nurse Practitioner, Family providers in Rice Lake
- 1194686469
- 1194554600
- 1912110305
- 1942176839
- 1306434246
- 1447609540
- 1386958676
- 1114578457
- 1598115537
- 1962436162
- 1679079859
- 1467389056