Carlos H. Zem, MD
NPI 1437237914ActiveIndividual· Internal Medicine, Nephrology· San Antonio, TX
Internal Medicine, Nephrology (MD) with Renal Associates, P.A., practicing in San Antonio, Texas. Their prescriptions cost Medicare Part D more than their services did: $1,006,083 for 2,921 claims, against $180,349 paid for services in 2024. Opko Pharmaceuticals, LLC was the largest of 4 companies reporting payments in 2025, $264.01 in all, mostly food and beverage. Lists Baptist Medical Center and 2 other hospitals as hospital affiliations.
Overview
| NPI | 1437237914 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Nov 1, 2006 |
| Last updated in NPPES | Mar 14, 2025 |
| Certified by provider | Mar 14, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Nephrology Primary | 207RN0300X | N2350 | 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 - Nephrology (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 276 |
|---|---|
| Services billed | 2,153 across 45 procedure codes |
| Paid by Medicare | $180,349 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,921 · 6,208 30-day fills |
|---|---|
| Patients | 361 |
| Total drug cost | $1,006,083 |
| Generic share | 77% of claims |
Education and affiliations
| Graduation year | 2002 |
|---|---|
| Medicare specialty | Nephrology |
| Telehealth | Offers telehealth |
Medical group
- Renal Associates, P.A.Seguin, TX · 40 clinicians
Hospital affiliations
- Baptist Medical CenterSan Antonio, TX
- Methodist HospitalSan Antonio, TX
- Methodist Hospital Stone OakSan Antonio, TX
Other facilities
- Davita Floresville DialysisDialysis facility · Floresville, TX
- Fmc - Alamo City DialysisDialysis facility · San Antonio, TX
- Guadalupe Kidney Disease ClDialysis facility · San Antonio, TX
- Kidney Disease Clinic of Central San AntonioDialysis facility · San Antonio, TX
Industry payments (Open Payments)
- 2025$264.01 · 5 payments from 4 companies
- 2024$215.91 · 5 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Opko Pharmaceuticals, LLC | $180.46 | 1 |
| Lilly USA, LLC | $48.21 | 2 |
| Scpharmaceuticals Inc. | $20.10 | 1 |
| Glaxosmithkline, LLC. | $15.24 | 1 |
What the 2025 payments were for
- Food and Beverage$264.01 · 5 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 168 nephrologists in San Antonio · All nephrologists in Texas