Shannon Marek, M.D.
NPI 1528282050 · Gastroenterology Physician · San Marcos, TX
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Shannon Marek, M.D. is a Gastroenterology Physician provider in San Marcos, TX (NPI 1528282050).
Provider details
- NPI number
- 1528282050
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 27100 (AL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
1,151 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 253 | $234 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 201 | $33 |
| Insertion of Guide Wire With Dilation of Esophagus Using a Flexible Endoscope43248 | 139 | $110 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 121 | $120 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 102 | $158 |
| Biopsy of Large Bowel Using a Flexible Endoscope |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 22 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Pantoprazole Sodium | 671 | 289 |
| Omeprazole | 173 | 74 |
| Sod Picosulf/Mag Ox/Citric Acbrand: Clenpiq | 136 | 132 |
| Sodium Chloride/Nahco3/Kcl/Pegbrand: Peg 3350-Electrolyte | 123 | 117 |
| Sucralfate | 77 | 44 |
| Famotidine | 43 | 14 |
| Esomeprazole Magnesium | 42 | 17 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,542 across 82 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-04-13
- Last updated
- 2013-02-20
Frequently asked questions
- What is Shannon Marek's NPI number?
- Shannon Marek's National Provider Identifier (NPI) is 1528282050, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Shannon Marek's specialty?
- Shannon Marek is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Shannon Marek located?
- Shannon Marek's practice location on file with NPPES is 1305 Wonder World Dr, San Marcos, TX 78666-7546.
- What is Shannon Marek's phone number?
- The practice phone number listed in the NPPES registry for Shannon Marek is (512) 754-8676.
- Does Shannon Marek accept Medicare?
- Shannon Marek is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Shannon Marek's NPI active?
- Yes — Shannon Marek's NPI (1528282050) is active in the NPPES registry as of the last update on 2013-02-20.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.