Diana Diaz, NP
NPI 1396321998ActiveIndividual· Nurse Practitioner, Family· Petaluma, CA
Nurse Practitioner, Family (NP) with Northbay Physicians Surgery Center, LLC and 1 other group, practicing in Petaluma, California. 524 Medicare patients in 2024, $54,171 paid; nearly all of their 97 Part D prescriptions were generic (92%). Lilly USA, LLC was the largest of 2 companies reporting payments in 2025, $143.91 in all, mostly food and beverage. Lists Northbay Medical Center as a hospital affiliation.
Overview
| NPI | 1396321998 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | NP |
| Sole proprietor | No |
| NPI issued | Mar 23, 2021 |
| Last updated in NPPES | Mar 23, 2021 |
| Certified by provider | Mar 23, 2021 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Nurse Practitioner, Family Primary | 363LF0000X | 95015657 | 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 | 524 |
|---|---|
| Services billed | 685 across 8 procedure codes |
| Paid by Medicare | $54,171 |
Part D prescriptions in 2024
| Prescriptions (claims) | 97 · 150 30-day fills |
|---|---|
| Patients | 42 |
| Total drug cost | $5,208 |
| Generic share | 92% of claims |
Education and affiliations
| Graduation year | 1994 |
|---|---|
| Medicare specialty | Nurse Practitioner |
| Telehealth | Offers telehealth |
Medical groups
- Northbay Physicians Surgery Center, LLCFairfield, CA · 324 clinicians
- Northbay Health Medical FoundationFairfield, CA · 213 clinicians
Hospital affiliation
- Northbay Medical CenterFairfield, CA
Industry payments (Open Payments)
- 2025$143.91 · 3 payments from 2 companies
- 2024$322.63 · 8 payments from 6 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Lilly USA, LLC | $94.48 | 1 |
| Bayer Healthcare Pharmaceuticals Inc. | $49.43 | 2 |
What the 2025 payments were for
- Food and Beverage$143.91 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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