Rex L. Mahnensmith, M.D.
NPI 1760466528ActiveIndividual· Internal Medicine· Waterbury, CT
Internal Medicine (M.D.) in Waterbury, Connecticut, trained at Yale University School of Medicine (class of 1977). Their prescriptions cost Medicare Part D more than their services did: $254,002 for 2,837 claims, against $19,106 paid for services in 2024. Astrazeneca Pharmaceuticals LP was the largest of 5 companies reporting payments in 2025, $142.04 in all, mostly food and beverage.
Overview
| NPI | 1760466528 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Dec 5, 2005 |
| Last updated in NPPES | Oct 22, 2015 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | 021731 | CT |
| Internal Medicine, Nephrology | 207RN0300X | 021731 | CT |
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 (CT) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 83 |
|---|---|
| Services billed | 400 across 30 procedure codes |
| Paid by Medicare | $19,106 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,837 · 4,676 30-day fills |
|---|---|
| Patients | 223 |
| Total drug cost | $254,002 |
| Generic share | 85% of claims |
Education and affiliations
| Medical school | Yale University School of Medicine |
|---|---|
| Graduation year | 1977 |
| Medicare specialty | Internal Medicine |
Medical groups
- CT Medical Group Inc.Orange, CT · 37 clinicians
- Docs Medical IncEast Haven, CT · 30 clinicians
Industry payments (Open Payments)
- 2025$142.04 · 6 payments from 5 companies
- 2024$481.92 · 43 payments from 5 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Astrazeneca Pharmaceuticals LP | $31.08 | 2 |
| Amgen Inc. | $30.00 | 1 |
| Calliditas Therapeutics US Inc. | $29.81 | 1 |
| Exact Sciences Corporation | $29.62 | 1 |
| Indivior Inc. | $21.53 | 1 |
What the 2025 payments were for
- Food and Beverage$142.04 · 6 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 134 internal medicine physicians in Waterbury · All internal medicine physicians in Connecticut