Mark Clayton Stahl, D.O.
NPI 1912932476ActiveIndividual· Allergy & Immunology· San Antonio, TX
Allergy & Immunology (D.O.) in San Antonio, Texas, trained at Michigan State University College of Osteopathic Medicine (class of 2003). In 2024 Medicare paid $370,370 for 106 patients, and Part D covered 682 of their prescriptions, 61% of them generic. Genzyme Corporation was the largest of 24 companies reporting payments in 2025, $6,788 in all, mostly food and beverage.
Overview
| NPI | 1912932476 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | No |
| NPI issued | Jul 12, 2006 |
| Last updated in NPPES | Apr 29, 2021 |
| Certified by provider | Apr 29, 2021 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Allergy & Immunology Primary | 207K00000X | P9742 | TX |
| Pediatrics | 208000000X | 34.010391 | OH |
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 - Allergy/Immunology (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 106 |
|---|---|
| Services billed | 16,236 across 37 procedure codes |
| Paid by Medicare | $370,370 |
Part D prescriptions in 2024
| Prescriptions (claims) | 682 · 924 30-day fills |
|---|---|
| Patients | 121 |
| Total drug cost | $236,899 |
| Generic share | 61% of claims |
Education and affiliations
| Medical school | Michigan State University College of Osteopathic Medicine |
|---|---|
| Graduation year | 2003 |
| Medicare specialty | Allergy/Immunology |
| Secondary specialties | Pediatric Medicine |
Medical group
- Apex Allergy and Asthma, PLLCSan Antonio, TX · 2 clinicians
Industry payments (Open Payments)
- 2025$6,788 · 204 payments from 24 companies
- 2024$7,768 · 159 payments from 20 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Genzyme Corporation | $2,401 | 16 |
| Astrazeneca Pharmaceuticals LP | $917.66 | 37 |
| Genentech USA, Inc. | $381.45 | 8 |
| Glaxosmithkline, LLC. | $366.19 | 25 |
| Ars Pharmaceuticals Operations, Inc. | $327.93 | 18 |
What the 2025 payments were for
- Food and Beverage$5,001 · 201 payments
- Consulting Fee$1,753 · 2 payments
- Education$34.00 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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