Garrett Greenan, MD
NPI 1225579584ActiveIndividual· Internal Medicine, Gastroenterology· Davidson, NC
Internal Medicine, Gastroenterology (MD) in Davidson, North Carolina, trained at University of Maryland School of Medicine (class of 2017). Their prescriptions cost Medicare Part D more than their services did: $808,755 for 1,651 claims, against $205,969 paid for services in 2024. Abbvie Inc. was the largest of 23 companies reporting payments in 2025, $4,066 in all, mostly food and beverage.
Overview
| NPI | 1225579584 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Mar 20, 2017 |
| Last updated in NPPES | Jan 13, 2026 |
| Certified by provider | Jan 13, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 2023-01019 | NC |
| Internal Medicine, Gastroenterology | 207RG0100X | 2020011722 | MO |
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 - Internal Medicine (NC) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 542 |
|---|---|
| Services billed | 3,702 across 35 procedure codes |
| Paid by Medicare | $205,969 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,651 · 3,029 30-day fills |
|---|---|
| Patients | 620 |
| Total drug cost | $808,755 |
| Generic share | 75% of claims |
Education and affiliations
| Medical school | University of Maryland School of Medicine |
|---|---|
| Graduation year | 2017 |
| Medicare specialty | Internal Medicine |
Medical group
- Carolina Digestive Health Associates PACharlotte, NC · 45 clinicians
Hospital affiliations
- Atrium Health University CityCharlotte, NC
- Carolinas Medical Center-NortheastConcord, NC
- Carolinas Medical Center/Behav HealthCharlotte, NC
- Novant Health Huntersville Medical CenterHuntersville, NC
- Novant Health Presbyterian Medical CenterCharlotte, NC
Industry payments (Open Payments)
- 2025$4,066 · 210 payments from 23 companies
- 2024$3,498 · 187 payments from 22 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $624.15 | 37 |
| Janssen Biotech, Inc. | $448.16 | 20 |
| Aimmune Therapeutics, Inc. | $328.12 | 13 |
| Madrigal Pharmaceuticals | $299.59 | 13 |
| Lilly USA, LLC | $290.56 | 15 |
What the 2025 payments were for
- Food and Beverage$3,947 · 207 payments
- Education$118.68 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records