Katherine Madison Macmillan, M.D.
NPI 1780117416ActiveIndividual· Internal Medicine, Gastroenterology· Simpsonville, SC
Internal Medicine, Gastroenterology (M.D.) with Prisma Health University Medical Group, practicing in Simpsonville, South Carolina. Their prescriptions cost Medicare Part D more than their services did: $10,220 for 19 claims, against $2,746 paid for services in 2024. Boston Scientific Corporation was the largest of 15 companies reporting payments in 2025, $4,563 in all, mostly travel and lodging. Lists Prisma Health Patewood Hospital and 4 other hospitals as hospital affiliations.
Overview
| NPI | 1780117416 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Apr 10, 2017 |
| Last updated in NPPES | Feb 23, 2026 |
| Certified by provider | Feb 23, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 85580 | SC |
| Internal Medicine | 207R00000X | 85580 | SC |
| Internal Medicine | 207R00000X | 009641 | GA |
| Internal Medicine, Gastroenterology | 207RG0100X | 72379 | AZ |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Gastroenterology (AZ); Practitioner - Gastroenterology (SC) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 18 |
|---|---|
| Services billed | 28 across 12 procedure codes |
| Paid by Medicare | $2,746 |
Part D prescriptions in 2024
| Prescriptions (claims) | 19 · 25 30-day fills |
|---|---|
| Patients | 15 |
| Total drug cost | $10,220 |
| Generic share | 79% of claims |
Education and affiliations
| Graduation year | 2017 |
|---|---|
| Medicare specialty | Gastroenterology |
Medical group
- Prisma Health University Medical GroupGreenville, SC · 2,493 clinicians
Hospital affiliations
- Prisma Health Patewood HospitalGreenville, SC
- Prisma Health Baptist Easley HospitalEasley, SC
- Prisma Health Greenville Memorial HospitalGreenville, SC
- Prisma Health Hillcrest HospitalSimpsonville, SC
- Prisma Health Laurens County HospitalClinton, SC
Other facilities
- Prisma Health North Greenville LtachLong-term care hospital · Travelers Rest, SC
Industry payments (Open Payments)
- 2025$4,563 · 43 payments from 15 companies
- 2024$40.65 · 2 payments from 2 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Boston Scientific Corporation | $3,371 | 16 |
| Ovesco Endoscopy USA, Inc. | $429.22 | 1 |
| Janssen Biotech, Inc. | $208.78 | 6 |
| Erbe USA Inc | $157.98 | 1 |
| Genzyme Corporation | $77.91 | 3 |
What the 2025 payments were for
- Travel and Lodging$3,235 · 11 payments
- Food and Beverage$1,328 · 32 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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