Mallory Erin Frances Callahan, NP
NPI 1528778214ActiveIndividual· Nurse Practitioner· Stanford, CA
Nurse Practitioner (NP) with Stanford Health Care, practicing in Stanford, California. Their prescriptions cost Medicare Part D more than their services did: $140,072 for 437 claims, against $29,353 paid for services in 2024. Lists Stanford Health Care and 1 other hospital as hospital affiliations.
Overview
| NPI | 1528778214 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | NP |
| Sole proprietor | No |
| NPI issued | Dec 2, 2022 |
| Last updated in NPPES | Dec 30, 2025 |
| Certified by provider | Dec 30, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Nurse Practitioner Primary | 363L00000X | 95023364 | CA |
| Nurse Practitioner, Adult Health | 363LA2200X | 95023364 | CA |
| Nurse Practitioner, Gerontology | 363LG0600X | 95023364 | CA |
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) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 275 |
|---|---|
| Services billed | 371 across 10 procedure codes |
| Paid by Medicare | $29,353 |
Part D prescriptions in 2024
| Prescriptions (claims) | 437 · 711 30-day fills |
|---|---|
| Patients | 167 |
| Total drug cost | $140,072 |
| Generic share | 75% of claims |
Education and affiliations
| Graduation year | 2022 |
|---|---|
| Medicare specialty | Nurse Practitioner |
| Telehealth | Offers telehealth |
Medical group
- Stanford Health CareStanford, CA · 3,122 clinicians
Hospital affiliations
- Stanford Health CareStanford, CA
- Stanford Health Care Tri-ValleyPleasanton, CA
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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