Leif William Ellisen, MD PHD
NPI 1225028533ActiveIndividual· Internal Medicine, Medical Oncology· Boston, MA
Internal Medicine, Medical Oncology (MD PHD) in Boston, Massachusetts, trained at Stanford University School of Medicine (class of 1992). Mostly services rather than prescriptions: Medicare paid $7,651 for 71 patients in 2024, with only 15 Part D claims. Stemline Therapeutics Inc. was the largest of 3 companies reporting payments in 2025, $4,119 in all, mostly consulting fees.
Overview
| NPI | 1225028533 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD PHD |
| Sole proprietor | No |
| NPI issued | Oct 27, 2005 |
| Last updated in NPPES | Oct 22, 2012 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Medical Oncology Primary | 207RX0202X | 79659 | MA |
| Internal Medicine | 207R00000X | 79659 | MA |
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 (MA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 71 |
|---|---|
| Services billed | 95 across 6 procedure codes |
| Paid by Medicare | $7,651 |
Part D prescriptions in 2024
| Prescriptions (claims) | 15 · 37 30-day fills |
|---|---|
| Total drug cost | $192.71 |
| Generic share | 100% of claims |
Education and affiliations
| Medical school | Stanford University School of Medicine |
|---|---|
| Graduation year | 1992 |
| Medicare specialty | Hematology/Oncology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical groups
- Massachusetts General Physicians Organization IncBoston, MA · 3,558 clinicians
- The General Hospital CorporationBoston, MA · 1,267 clinicians
Hospital affiliations
- Massachusetts General HospitalBoston, MA
- Newton-Wellesley HospitalNewton, MA
Industry payments (Open Payments)
- 2025$4,119 · 6 payments from 3 companies
- 2024$6,560 · 1 payment from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Stemline Therapeutics Inc. | $2,859 | 3 |
| Gilead Sciences, Inc. | $1,216 | 2 |
| Astrazeneca Pharmaceuticals LP | $43.25 | 1 |
What the 2025 payments were for
- Consulting Fee$3,890 · 2 payments
- Food and Beverage$185.57 · 3 payments
- Education$43.25 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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