Gustavo Horacio Day, M.D.
NPI 1538239173ActiveIndividual· Internal Medicine· Dallas, TX
Internal Medicine (M.D.) in Dallas, Texas, licensed in TX, with an NPI issued in November 2006. Their prescriptions cost Medicare Part D more than their services did: $3,974,464 for 34,251 claims, against $255,598 paid for services in 2024. Novo Nordisk Inc was the largest of 37 companies reporting payments in 2025, $5,181 in all, mostly food and beverage. Lists Medical City Dallas Hospital and 2 other hospitals as hospital affiliations.
Overview
| NPI | 1538239173 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | Yes |
| NPI issued | Nov 9, 2006 |
| Last updated in NPPES | May 18, 2026 |
| Certified by provider | May 18, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | K1411 | 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 - Internal Medicine (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 356 |
|---|---|
| Services billed | 7,090 across 129 procedure codes |
| Paid by Medicare | $255,598 |
Part D prescriptions in 2024
| Prescriptions (claims) | 34,251 · 65,499 30-day fills |
|---|---|
| Patients | 1,405 |
| Total drug cost | $3,974,464 |
| Generic share | 87% of claims |
Education and affiliations
| Graduation year | 1990 |
|---|---|
| Medicare specialty | Internal Medicine |
Hospital affiliations
- Medical City Dallas HospitalDallas, TX
- Medical City LewisvilleLewisville, TX
- Medical City PlanoPlano, TX
Other facilities
- Angel Home Healthcare ServicesHome health agency · Mesquite, TX
- Healing Hands Healthcare LLCHome health agency · Wichita Falls, TX
- Rehab at Home Healthcare ServicesHome health agency · Arlington, TX
Industry payments (Open Payments)
- 2025$5,181 · 263 payments from 37 companies
- 2024$4,730 · 270 payments from 32 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novo Nordisk Inc | $512.41 | 22 |
| Astrazeneca Pharmaceuticals LP | $454.29 | 30 |
| Scilex Pharmaceuticals Inc. | $428.55 | 5 |
| Abbvie Inc. | $398.42 | 31 |
| Abbott Laboratories | $352.51 | 8 |
What the 2025 payments were for
- Food and Beverage$5,181 · 263 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 1,234 internal medicine physicians in Dallas · All internal medicine physicians in Texas