John E. Greifenkamp, MD
NPI 1396712980ActiveIndividual· Internal Medicine· Longview, TX
Internal Medicine (MD) in Longview, Texas, licensed in TX, with an NPI issued in March 2006. Part D covered 117 prescriptions written in 2024, 85% of them generic. Alnylam Pharmaceuticals Inc. was the largest of 2 companies reporting payments in 2025, $147.76 in all, mostly food and beverage.
Overview
| NPI | 1396712980 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Mar 2, 2006 |
| Last updated in NPPES | Jan 15, 2008 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | E0479 | 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) | Not in the public enrollment file of Oct 1, 2026 |
|---|
Part D prescriptions in 2024
| Prescriptions (claims) | 117 · 199 30-day fills |
|---|---|
| Patients | 40 |
| Total drug cost | $12,156 |
| Generic share | 85% of claims |
Industry payments (Open Payments)
- 2025$147.76 · 2 payments from 2 companies
- 2024$30.62 · 2 payments from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Alnylam Pharmaceuticals Inc. | $133.10 | 1 |
| Philips North America LLC | $14.66 | 1 |
What the 2025 payments were for
- Food and Beverage$147.76 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
Other internal medicine physicians in Longview
- 1023420999
- 1083119754
- 1093127284
- 1124505300
- 1154633774
- 1174878540
- 1184869950
- 1194137331
- 1205248424
- 1205803079
- 1215255179
- 1215904610
All 119 internal medicine physicians in Longview · All internal medicine physicians in Texas