Norman M. Callahan, D.O.
NPI 1851367783ActiveIndividual· Internal Medicine, Gastroenterology· Malvern, PA
Internal Medicine, Gastroenterology (D.O.) in Malvern, Pennsylvania, trained at Philadelphia College of Osteopathic Medicine (class of 1991). Their prescriptions cost Medicare Part D more than their services did: $1,264,302 for 932 claims, against $227,764 paid for services in 2024. Abbvie Inc. was the largest of 19 companies reporting payments in 2025, $1,863 in all, mostly food and beverage.
Overview
| NPI | 1851367783 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | No |
| NPI issued | Feb 28, 2006 |
| Last updated in NPPES | Aug 5, 2009 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | OS007658-L | PA |
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 - Gastroenterology (PA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 713 |
|---|---|
| Services billed | 9,820 across 56 procedure codes |
| Paid by Medicare | $227,764 |
Part D prescriptions in 2024
| Prescriptions (claims) | 932 · 2,056 30-day fills |
|---|---|
| Patients | 273 |
| Total drug cost | $1,264,302 |
| Generic share | 88% of claims |
Education and affiliations
| Medical school | Philadelphia College of Osteopathic Medicine |
|---|---|
| Graduation year | 1991 |
| Medicare specialty | Gastroenterology |
Medical group
- Regional Gastroenterology Associates of Lancaster, Ltd.Lancaster, PA · 244 clinicians
Hospital affiliations
- Bryn Mawr HospitalBryn Mawr, PA
- Chester County HospitalWest Chester, PA
- Hospital of Univ of PennsylvaniaPhiladelphia, PA
- Main Line Hospital LankenauWynnewood, PA
- Paoli HospitalPaoli, PA
Industry payments (Open Payments)
- 2025$1,863 · 89 payments from 19 companies
- 2024$1,811 · 82 payments from 15 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $394.30 | 23 |
| Janssen Biotech, Inc. | $293.95 | 12 |
| Pfizer Inc. | $194.73 | 11 |
| Ardelyx, Inc. | $154.83 | 7 |
| Qol Medical, LLC | $149.63 | 6 |
What the 2025 payments were for
- Food and Beverage$1,863 · 89 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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