Marie A. Hollenhorst, MD, PHD
NPI 1497193999ActiveIndividual· Internal Medicine, Hematology· Boston, MA
Internal Medicine, Hematology (MD, PHD) in Boston, Massachusetts, trained at Harvard Medical School (class of 2013). Mostly services rather than prescriptions: Medicare paid $8,937 for 36 patients in 2024, with only 12 Part D claims. Werfen USA LLC reported $55.82 in payments in 2025, mostly food and beverage.
Overview
| NPI | 1497193999 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD, PHD |
| Sole proprietor | No |
| NPI issued | Jun 6, 2013 |
| Last updated in NPPES | Feb 11, 2026 |
| Certified by provider | Feb 11, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology Primary | 207RH0000X | 262787 | MA |
| Internal Medicine | 207R00000X | 262787 | MA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Hematology (MA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 36 |
|---|---|
| Services billed | 105 across 11 procedure codes |
| Paid by Medicare | $8,937 |
Part D prescriptions in 2024
| Prescriptions (claims) | 12 · 20 30-day fills |
|---|---|
| Total drug cost | $7,067 |
Education and affiliations
| Medical school | Harvard Medical School |
|---|---|
| Graduation year | 2013 |
| Medicare specialty | Hematology |
| Telehealth | Offers telehealth |
Medical group
- Brigham and Womens Physicians Organization IncBoston, MA · 2,994 clinicians
Hospital affiliation
- Brigham and Women's HospitalBoston, MA
Industry payments (Open Payments)
- 2025$55.82 · 1 payment from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Werfen USA LLC | $55.82 | 1 |
What the 2025 payments were for
- Food and Beverage$55.82 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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