Mark Allen McClanahan, M.D.
NPI 1093840811ActiveIndividual· Internal Medicine, Endocrinology, Diabetes & Metabolism· Fredericksburg, VA
Internal Medicine, Endocrinology, Diabetes & Metabolism (M.D.) in Fredericksburg, Virginia, trained at Virginia Commonwealth University, School of Medicine (class of 1986). Their prescriptions cost Medicare Part D more than their services did: $3,662,765 for 8,143 claims, against $397,006 paid for services in 2024. Lilly USA, LLC was the largest of 3 companies reporting payments in 2025, $73.73 in all, mostly food and beverage.
Overview
| NPI | 1093840811 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Feb 22, 2007 |
| Last updated in NPPES | Apr 6, 2011 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Endocrinology, Diabetes & Metabolism Primary | 207RE0101X | 0101041309 | 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 - Endocrinology (VA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 1,541 |
|---|---|
| Services billed | 11,289 across 16 procedure codes |
| Paid by Medicare | $397,006 |
Part D prescriptions in 2024
| Prescriptions (claims) | 8,143 · 20,989 30-day fills |
|---|---|
| Patients | 1,017 |
| Total drug cost | $3,662,765 |
| Generic share | 48% of claims |
Education and affiliations
| Medical school | Virginia Commonwealth University, School of Medicine |
|---|---|
| Graduation year | 1986 |
| Medicare specialty | Endocrinology |
| Telehealth | Offers telehealth |
Hospital affiliations
- Fauquier HospitalWarrenton, VA
- Mary Washington HospitalFredericksburg, VA
- Stafford Hospital, LLCStafford, VA
Industry payments (Open Payments)
- 2025$73.73 · 3 payments from 3 companies
- 2024$489.22 · 25 payments from 15 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Lilly USA, LLC | $29.63 | 1 |
| Ibsa Pharma Inc. | $23.58 | 1 |
| Amgen Inc. | $20.52 | 1 |
What the 2025 payments were for
- Food and Beverage$73.73 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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