Shannon Marek, M.D.
NPI 1528282050ActiveIndividual· Internal Medicine, Gastroenterology· San Marcos, TX
Internal Medicine, Gastroenterology (M.D.) in San Marcos, Texas, trained at University of Texas Medical School at Houston (class of 2004). Their prescriptions cost Medicare Part D more than their services did: $605,028 for 1,793 claims, against $242,594 paid for services in 2024. Abbvie Inc. was the largest of 16 companies reporting payments in 2025, $1,025 in all, mostly food and beverage.
Overview
| NPI | 1528282050 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Apr 13, 2007 |
| Last updated in NPPES | Feb 20, 2013 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 059554 | GA |
| Internal Medicine | 207R00000X | 27100 | AL |
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 - Gastroenterology (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 599 |
|---|---|
| Services billed | 7,414 across 47 procedure codes |
| Paid by Medicare | $242,594 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,793 · 3,801 30-day fills |
|---|---|
| Patients | 668 |
| Total drug cost | $605,028 |
| Generic share | 77% of claims |
Education and affiliations
| Medical school | University of Texas Medical School at Houston |
|---|---|
| Graduation year | 2004 |
| Medicare specialty | Gastroenterology |
| Secondary specialties | Internal Medicine |
Medical group
- Texas Digestive Disease Consultants, PLLCFlower Mound, TX · 608 clinicians
Hospital affiliations
- Christus Santa Rosa Hospital-San MarcosSan Marcos, TX
- Resolute Health HospitalNew Braunfels, TX
Industry payments (Open Payments)
- 2025$1,025 · 46 payments from 16 companies
- 2024$1,542 · 82 payments from 19 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $171.77 | 9 |
| Janssen Scientific Affairs, LLC | $146.74 | 1 |
| Madrigal Pharmaceuticals | $94.29 | 5 |
| Salix Pharmaceuticals, A Division of Bausch Health US, LLC | $75.00 | 4 |
| Regeneron Healthcare Solutions, Inc. | $72.88 | 2 |
What the 2025 payments were for
- Food and Beverage$1,025 · 46 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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