Ythanh Duy Nguyen, MD
NPI 1255391181ActiveIndividual· Internal Medicine· Rancho Cucamonga, CA
Internal Medicine (MD) in Rancho Cucamonga, California, licensed in CA, with an NPI issued in March 2006. Their prescriptions cost Medicare Part D more than their services did: $354,196 for 2,357 claims, against $68,203 paid for services in 2024. Sanofi-Aventis U.S. LLC was the largest of 5 companies reporting payments in 2025, $136.45 in all, mostly food and beverage.
Overview
| NPI | 1255391181 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | Yes |
| NPI issued | Mar 24, 2006 |
| Last updated in NPPES | Dec 14, 2025 |
| Certified by provider | Dec 14, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | A84989 | 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 | 156 |
|---|---|
| Services billed | 685 across 12 procedure codes |
| Paid by Medicare | $68,203 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,357 · 4,228 30-day fills |
|---|---|
| Patients | 508 |
| Total drug cost | $354,196 |
| Generic share | 80% of claims |
Industry payments (Open Payments)
- 2025$136.45 · 5 payments from 5 companies
- 2024$121.41 · 5 payments from 3 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Sanofi-Aventis U.S. LLC | $34.38 | 1 |
| Pfizer Inc. | $28.40 | 1 |
| Alk-Abello, Inc | $25.04 | 1 |
| Astrazeneca Pharmaceuticals LP | $24.73 | 1 |
| Ardelyx, Inc. | $23.90 | 1 |
What the 2025 payments were for
- Food and Beverage$136.45 · 5 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 40 internal medicine physicians in Rancho Cucamonga · All internal medicine physicians in California