Mark J. Vellek, M.D.
NPI 1063409688ActiveIndividual· Internal Medicine, Hematology & Oncology· Las Vegas, NV
Internal Medicine, Hematology & Oncology (M.D.) in Las Vegas, Nevada, trained at University of Minnesota Medical School (class of 1986). Their prescriptions cost Medicare Part D more than their services did: $3,036,614 for 981 claims, against $80,097 paid for services in 2024. Astrazeneca Pharmaceuticals LP was the largest of 23 companies reporting payments in 2025, $1,636 in all, mostly food and beverage.
Overview
| NPI | 1063409688 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Sep 29, 2005 |
| Last updated in NPPES | Dec 12, 2023 |
| Certified by provider | Dec 12, 2023 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology & Oncology Primary | 207RH0003X | 20944 | NV |
| Internal Medicine, Hematology & Oncology | 207RH0003X | C2194 | KY |
| Internal Medicine, Hematology & Oncology | 207RH0003X | R5H89 | MO |
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 (NV) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 412 |
|---|---|
| Services billed | 1,157 across 13 procedure codes |
| Paid by Medicare | $80,097 |
Part D prescriptions in 2024
| Prescriptions (claims) | 981 · 1,271 30-day fills |
|---|---|
| Patients | 220 |
| Total drug cost | $3,036,614 |
| Generic share | 79% of claims |
Education and affiliations
| Medical school | University of Minnesota Medical School |
|---|---|
| Graduation year | 1986 |
| Medicare specialty | Hematology/Oncology |
Hospital affiliations
- Carson Tahoe Regional Medical CenterCarson City, NV
- Murray-Calloway County HospitalMurray, KY
Industry payments (Open Payments)
- 2025$1,636 · 87 payments from 23 companies
- 2024$1,115 · 61 payments from 26 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astrazeneca Pharmaceuticals LP | $197.22 | 9 |
| Merck Sharp & Dohme LLC | $190.86 | 11 |
| Pfizer Inc. | $158.02 | 11 |
| Abbvie Inc. | $105.04 | 5 |
| Gilead Sciences, Inc. | $101.78 | 6 |
What the 2025 payments were for
- Food and Beverage$1,593 · 86 payments
- Education$43.25 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 66 hematologist-oncologists in Las Vegas · All hematologist-oncologists in Nevada