Gregory Yervant Warner, D.O.
NPI 1073704326ActiveIndividual· Internal Medicine, Infectious Disease· Vacaville, CA
Internal Medicine, Infectious Disease (D.O.) with Northbay Physicians Surgery Center, LLC and 1 other group, practicing in Vacaville, California. Their prescriptions cost Medicare Part D more than their services did: $1,178,301 for 836 claims, against $109,073 paid for services in 2024. Abbvie Inc. was the largest of 3 companies reporting payments in 2025, $121.08 in all, mostly food and beverage. Lists Northbay Medical Center and 1 other hospital as hospital affiliations.
Overview
| NPI | 1073704326 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | Yes |
| NPI issued | Aug 1, 2007 |
| Last updated in NPPES | Sep 17, 2013 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Infectious Disease Primary | 207RI0200X | 20A9902 | CA |
| Internal Medicine | 207R00000X | 20A9902 | 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 - Infectious Disease (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 317 |
|---|---|
| Services billed | 1,593 across 12 procedure codes |
| Paid by Medicare | $109,073 |
Part D prescriptions in 2024
| Prescriptions (claims) | 836 · 1,177 30-day fills |
|---|---|
| Patients | 133 |
| Total drug cost | $1,178,301 |
| Generic share | 67% of claims |
Education and affiliations
| Graduation year | 2005 |
|---|---|
| Medicare specialty | Infectious Disease |
| Telehealth | Offers telehealth |
Medical groups
- Northbay Physicians Surgery Center, LLCFairfield, CA · 324 clinicians
- Northbay Health Medical FoundationFairfield, CA · 213 clinicians
Hospital affiliations
- Northbay Medical CenterFairfield, CA
- Sutter Medical Center, SacramentoSacramento, CA
Other facilities
- Healthflex Home Health ServicesHome health agency · Oakland, CA
Industry payments (Open Payments)
- 2025$121.08 · 5 payments from 3 companies
- 2024$180.75 · 8 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $79.27 | 3 |
| Viiv Healthcare Company | $22.34 | 1 |
| Tanabe Pharma America, Inc. | $19.47 | 1 |
What the 2025 payments were for
- Food and Beverage$121.08 · 5 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other Internal Medicine, Infectious Disease providers in Vacaville
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- 1760758726
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