Thomas Yang Sun, MD
NPI 1215468160ActiveIndividual· Internal Medicine, Medical Oncology· Pleasanton, CA
Internal Medicine, Medical Oncology (MD) in Pleasanton, California, trained at Yale University School of Medicine (class of 2017). Their prescriptions cost Medicare Part D more than their services did: $1,162,567 for 762 claims, against $730,363 paid for services in 2024. Pfizer Inc. was the largest of 3 companies reporting payments in 2025, $83.60 in all, mostly food and beverage.
Overview
| NPI | 1215468160 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Mar 22, 2017 |
| Last updated in NPPES | Apr 29, 2024 |
| Certified by provider | Apr 29, 2024 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Medical Oncology Primary | 207RX0202X | A157081 | CA |
| Internal Medicine | 207R00000X | A157081 | CA |
| Internal Medicine, Hematology | 207RH0000X | A157081 | 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 - Hematology/Oncology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 365 |
|---|---|
| Services billed | 31,260 across 85 procedure codes |
| Paid by Medicare | $730,363 |
Part D prescriptions in 2024
| Prescriptions (claims) | 762 · 1,010 30-day fills |
|---|---|
| Patients | 124 |
| Total drug cost | $1,162,567 |
| Generic share | 77% of claims |
Education and affiliations
| Medical school | Yale University School of Medicine |
|---|---|
| Graduation year | 2017 |
| Medicare specialty | Hematology/Oncology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Stanford Health CareStanford, CA · 3,122 clinicians
Hospital affiliations
- Alta Bates Summit Medical Center - Alta Bates CampBerkeley, CA
- Stanford Health CareStanford, CA
- Stanford Health Care Tri-ValleyPleasanton, CA
Industry payments (Open Payments)
- 2025$83.60 · 3 payments from 3 companies
- 2024$156.01 · 6 payments from 6 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Pfizer Inc. | $30.65 | 1 |
| Abbvie Inc. | $27.82 | 1 |
| Teleflex LLC | $25.13 | 1 |
What the 2025 payments were for
- Food and Beverage$52.95 · 2 payments
- Education$30.65 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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