Isaiah Mark Horton, MD
NPI 1053803940ActiveIndividual· Internal Medicine· Redlands, CA
Internal Medicine (MD) in Redlands, California, trained at Loma Linda University School of Medicine (class of 2018). Mostly services rather than prescriptions: Medicare paid $1,728 for 13 patients in 2024, with only 18 Part D claims.
Overview
| NPI | 1053803940 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Jun 5, 2018 |
| Last updated in NPPES | Dec 17, 2025 |
| Certified by provider | Dec 17, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | A200368 | CA |
| Internal Medicine | 207R00000X | 0101268175 | VA |
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 (CA); Practitioner - Internal Medicine (MD); Practitioner - Internal Medicine (VA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 13 |
|---|---|
| Services billed | 22 across 6 procedure codes |
| Paid by Medicare | $1,728 |
Part D prescriptions in 2024
| Prescriptions (claims) | 18 · 32 30-day fills |
|---|---|
| Total drug cost | $736.78 |
| Generic share | 89% of claims |
Education and affiliations
| Medical school | Loma Linda University School of Medicine |
|---|---|
| Graduation year | 2018 |
| Medicare specialty | Internal Medicine |
Medical group
- Southern California Permanente Medical GroupRedlands, CA · 11,293 clinicians
Hospital affiliations
- Barstow Community HospitalBarstow, CA
- Kaiser Foundation Hospital Fontana/OntarioFontana, CA
Industry payments (Open Payments)
None reported for 2025 or 2024.
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 78 internal medicine physicians in Redlands · All internal medicine physicians in California