Tomoko Hirabayashi Williams, MSN, RN, FNP-C
NPI 1255896262ActiveIndividual· Nurse Practitioner, Family· Irvine, CA
Nurse Practitioner, Family (MSN, RN, FNP-C) with Texas Oncology PA and 1 other group, practicing in Irvine, California. Their prescriptions cost Medicare Part D more than their services did: $138,924 for 519 claims, against $59,699 paid for services in 2024. Novartis Pharmaceuticals Corporation was the largest of 32 companies reporting payments in 2025, $2,416 in all, mostly food and beverage.
Overview
| NPI | 1255896262 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MSN, RN, FNP-C |
| Sole proprietor | No |
| NPI issued | Feb 4, 2019 |
| Last updated in NPPES | Feb 6, 2026 |
| Certified by provider | Feb 6, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Nurse Practitioner, Family Primary | 363LF0000X | NP95037243 | CA |
| Nurse Practitioner, Family | 363LF0000X | AP140322 | TX |
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 - Nurse Practitioner (CA); Practitioner - Nurse Practitioner (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 336 |
|---|---|
| Services billed | 2,122 across 49 procedure codes |
| Paid by Medicare | $59,699 |
Part D prescriptions in 2024
| Prescriptions (claims) | 519 · 643 30-day fills |
|---|---|
| Patients | 163 |
| Total drug cost | $138,924 |
| Generic share | 92% of claims |
Education and affiliations
| Graduation year | 2018 |
|---|---|
| Medicare specialty | Nurse Practitioner |
| Telehealth | Offers telehealth |
Medical groups
- Texas Oncology PAPlano, TX · 1,014 clinicians
- City of Hope Medical FoundationDuarte, CA · 982 clinicians
Industry payments (Open Payments)
- 2025$2,416 · 106 payments from 32 companies
- 2024$1,548 · 67 payments from 23 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novartis Pharmaceuticals Corporation | $295.08 | 13 |
| Janssen Biotech, Inc. | $254.23 | 15 |
| Lilly USA, LLC | $171.34 | 6 |
| Pfizer Inc. | $149.70 | 6 |
| Astrazeneca Pharmaceuticals LP | $140.16 | 7 |
What the 2025 payments were for
- Food and Beverage$2,416 · 106 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 166 family nurse practitioners in Irvine · All family nurse practitioners in California