Margaret Mary Sullivan, MD
NPI 1134330178ActiveIndividual· Internal Medicine, Cardiovascular Disease· Ennis, TX
Internal Medicine, Cardiovascular Disease (MD) in Ennis, Texas, trained at University of Texas Medical School at San Antonio (class of 2004). Their prescriptions cost Medicare Part D more than their services did: $930,275 for 4,107 claims, against $81,384 paid for services in 2024. Merck Sharp & Dohme LLC was the largest of 7 companies reporting payments in 2025, $266.77 in all, mostly food and beverage.
Overview
| NPI | 1134330178 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | Yes |
| NPI issued | May 24, 2007 |
| Last updated in NPPES | Aug 16, 2017 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Cardiovascular Disease Primary | 207RC0000X | N5421 | TX |
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 - Cardiovascular Disease (Cardiology) (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 405 |
|---|---|
| Services billed | 1,373 across 37 procedure codes |
| Paid by Medicare | $81,384 |
Part D prescriptions in 2024
| Prescriptions (claims) | 4,107 · 7,454 30-day fills |
|---|---|
| Patients | 394 |
| Total drug cost | $930,275 |
| Generic share | 73% of claims |
Education and affiliations
| Medical school | University of Texas Medical School at San Antonio |
|---|---|
| Graduation year | 2004 |
| Medicare specialty | Cardiovascular Disease (Cardiology) |
Medical group
- Texas Specialty PhysiciansEnnis, TX · 64 clinicians
Hospital affiliations
Industry payments (Open Payments)
- 2025$266.77 · 13 payments from 7 companies
- 2024$216.70 · 12 payments from 7 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Merck Sharp & Dohme LLC | $75.39 | 4 |
| Novo Nordisk Inc | $63.04 | 3 |
| Medtronic, Inc. | $53.04 | 2 |
| Corcept Therapeutics | $20.07 | 1 |
| Scpharmaceuticals Inc. | $18.78 | 1 |
What the 2025 payments were for
- Food and Beverage$266.77 · 13 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records