Mark Byron Jennings, MD
NPI 1336379783ActiveIndividual· Internal Medicine· Allen, TX
Internal Medicine (MD) in Allen, Texas, trained at University of Oklahoma College of Medicine (class of 2009). Their prescriptions cost Medicare Part D more than their services did: $5,994,930 for 2,398 claims, against $3,216,453 paid for services in 2024. Pfizer Inc. was the largest of 10 companies reporting payments in 2025, $728.28 in all, mostly food and beverage.
Overview
| NPI | 1336379783 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jul 20, 2009 |
| Last updated in NPPES | Sep 12, 2012 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | P1880 | TX |
| Student in an Organized Health Care Education/Training Program | 390200000X | — | — |
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 (OK) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 1,069 |
|---|---|
| Services billed | 170,397 across 212 procedure codes |
| Paid by Medicare | $3,216,453 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,398 · 2,998 30-day fills |
|---|---|
| Patients | 308 |
| Total drug cost | $5,994,930 |
| Generic share | 80% of claims |
Education and affiliations
| Medical school | University of Oklahoma College of Medicine |
|---|---|
| Graduation year | 2009 |
| Medicare specialty | Hematology/Oncology |
Medical groups
- Stillwater Medical Center AuthorityStillwater, OK · 153 clinicians
- Oklahoma Cancer Specialists and Research Institute, LLCTulsa, OK · 47 clinicians
Hospital affiliations
- Ascension St John Medical CenterTulsa, OK
- Cherokee Nation W W Hastings Indian HospitalTahlequah, OK
- Oklahoma State University Medical CenterTulsa, OK
- Stillwater Medical CenterStillwater, OK
- Stillwater Medical-BlackwellBlackwell, OK
Industry payments (Open Payments)
- 2025$728.28 · 35 payments from 10 companies
- 2024$738.48 · 40 payments from 12 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Pfizer Inc. | $231.03 | 20 |
| Astrazeneca Pharmaceuticals LP | $158.37 | 3 |
| Caris Mpi, Inc. | $140.77 | 2 |
| Beone Medicines USA, Inc. | $52.15 | 2 |
| Abbvie Inc. | $43.49 | 2 |
What the 2025 payments were for
- Food and Beverage$553.62 · 18 payments
- Education$174.66 · 17 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other internal medicine physicians in Allen
- 1073877700
- 1306333190
- 1316264971
- 1356320378
- 1437168671
- 1558329235
- 1629001318
- 1629208434
- 1649406281
- 1669642799
- 1780975128
- 1811335714
All 59 internal medicine physicians in Allen · All internal medicine physicians in Texas