Adrian Martin Casillas, MD
NPI 1871528125ActiveIndividual· Internal Medicine, Allergy & Immunology· El Paso, TX
Internal Medicine, Allergy & Immunology (MD) in El Paso, Texas, trained at University of California, Geffen School of Medicine (class of 1987). Their prescriptions cost Medicare Part D more than their services did: $245,303 for 740 claims, against $21,774 paid for services in 2024. Regeneron Healthcare Solutions, Inc. was the largest of 10 companies reporting payments in 2025, $924.43 in all, mostly food and beverage.
Overview
| NPI | 1871528125 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jul 12, 2006 |
| Last updated in NPPES | May 21, 2018 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Allergy & Immunology Primary | 207RA0201X | G63875 | CA |
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 | 72 |
|---|---|
| Services billed | 1,012 across 17 procedure codes |
| Paid by Medicare | $21,774 |
Part D prescriptions in 2024
| Prescriptions (claims) | 740 · 1,090 30-day fills |
|---|---|
| Patients | 165 |
| Total drug cost | $245,303 |
| Generic share | 79% of claims |
Education and affiliations
| Medical school | University of California, Geffen School of Medicine |
|---|---|
| Graduation year | 1987 |
| Medicare specialty | Allergy/Immunology |
| Secondary specialties | Internal Medicine |
Medical group
- Bhs Physicians Network, IncBrownsville, TX · 706 clinicians
Hospital affiliation
Industry payments (Open Payments)
- 2025$924.43 · 36 payments from 10 companies
- 2024$641.42 · 34 payments from 7 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Regeneron Healthcare Solutions, Inc. | $317.45 | 14 |
| Genzyme Corporation | $210.32 | 8 |
| Novartis Pharmaceuticals Corporation | $102.37 | 4 |
| Sanofi-Aventis U.S. LLC | $99.95 | 1 |
| Csl Behring | $48.49 | 2 |
What the 2025 payments were for
- Food and Beverage$824.48 · 35 payments
- Education$99.95 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records