Thomas Toan Nguyen, MD
NPI 1336272871ActiveIndividual· Internal Medicine· San Luis Obispo, CA
Internal Medicine (MD) with The Regents of the University of California, practicing in San Luis Obispo, California. Their prescriptions cost Medicare Part D more than their services did: $1,014,858 for 8,998 claims, against $102,140 paid for services in 2024. Exact Sciences Corporation was the largest of 2 companies reporting payments in 2025, $40.40 in all, mostly food and beverage. Lists Adventist Health Sierra Vista and 2 other hospitals as hospital affiliations.
Overview
| NPI | 1336272871 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Mar 13, 2007 |
| Last updated in NPPES | May 20, 2025 |
| Certified by provider | May 20, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | A97300 | 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 - Internal Medicine (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 486 |
|---|---|
| Services billed | 4,810 across 41 procedure codes |
| Paid by Medicare | $102,140 |
Part D prescriptions in 2024
| Prescriptions (claims) | 8,998 · 20,764 30-day fills |
|---|---|
| Patients | 730 |
| Total drug cost | $1,014,858 |
| Generic share | 87% of claims |
Education and affiliations
| Graduation year | 2003 |
|---|---|
| Medicare specialty | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- The Regents of the University of CaliforniaSanta Monica, CA · 1,462 clinicians
Hospital affiliations
- Adventist Health Sierra VistaSan Luis Obispo, CA
- French Hospital Medical CenterSan Luis Obispo, CA
- Marian Regional Medical CenterSanta Maria, CA
Other facilities
- Central Coast Home Health IncHome health agency · San Luis Obispo, CA
- Dignity Health Home HealthHome health agency · Santa Maria, CA
Industry payments (Open Payments)
- 2025$40.40 · 2 payments from 2 companies
- 2024$19.08 · 1 payment from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Exact Sciences Corporation | $20.62 | 1 |
| Pfizer Inc. | $19.78 | 1 |
What the 2025 payments were for
- Food and Beverage$40.40 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 52 internal medicine physicians in San Luis Obispo · All internal medicine physicians in California