Tam M. Nguyen, D.O.
Internal Medicine (D.O.) in Marysville, California, trained at Philadelphia College of Osteopathic Medicine (class of 1998). Their prescriptions cost Medicare Part D more than their services did: $445,376 for 9,435 claims, against $2,689 paid for services in 2024. Salix Pharmaceuticals, A Division of Bausch Health US, LLC reported $23.09 in payments in 2025, mostly food and beverage. A record with the same name and state is on the OIG exclusion list; it carries no NPI, so check it before acting.
Overview
| NPI | 1841200854 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | Yes |
| NPI issued | Aug 9, 2006 |
| Last updated in NPPES | Feb 11, 2022 |
| Certified by provider | Mar 30, 2020 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | 20A8322 | CA |
Exclusion screening
Possible match: verify before acting. The OIG list has a record with the same name in California, but that record carries no NPI, so it may be a different person or business.
| Matched by | Name on OIG list | Exclusion type | Excluded since | Location |
|---|---|---|---|---|
| Name + state | Tam Van Nguyen · Chiropractic | 1128a3 | Jul 19, 2012 | Westminster, CA |
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | Possible (name) | See above |
| 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 | 22 |
|---|---|
| Services billed | 59 across 15 procedure codes |
| Paid by Medicare | $2,689 |
Part D prescriptions in 2024
| Prescriptions (claims) | 9,435 · 21,893 30-day fills |
|---|---|
| Patients | 864 |
| Total drug cost | $445,376 |
| Generic share | 90% of claims |
Education and affiliations
| Medical school | Philadelphia College of Osteopathic Medicine |
|---|---|
| Graduation year | 1998 |
| Medicare specialty | Internal Medicine |
Medical group
- Permanente Medical Group IncOakland, CA · 10,996 clinicians
Industry payments (Open Payments)
- 2025$23.09 · 1 payment from 1 company
- 2024$38.44 · 2 payments from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Salix Pharmaceuticals, A Division of Bausch Health US, LLC | $23.09 | 1 |
What the 2025 payments were for
- Food and Beverage$23.09 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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