Mark T. Fahlen, MD
NPI 1679539415ActiveIndividual· Internal Medicine, Nephrology· Modesto, CA
Internal Medicine, Nephrology (MD) in Modesto, California, trained at Albany Medical College of Union University (class of 1998). Their prescriptions cost Medicare Part D more than their services did: $491,574 for 3,859 claims, against $256,349 paid for services in 2024.
Overview
| NPI | 1679539415 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | Yes |
| NPI issued | Apr 21, 2006 |
| Last updated in NPPES | Aug 2, 2011 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Nephrology Primary | 207RN0300X | A81212 | CA |
| Internal Medicine | 207R00000X | A81212 | CA |
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 - Nephrology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 432 |
|---|---|
| Services billed | 2,258 across 13 procedure codes |
| Paid by Medicare | $256,349 |
Part D prescriptions in 2024
| Prescriptions (claims) | 3,859 · 6,709 30-day fills |
|---|---|
| Patients | 294 |
| Total drug cost | $491,574 |
| Generic share | 82% of claims |
Education and affiliations
| Medical school | Albany Medical College of Union University |
|---|---|
| Graduation year | 1998 |
| Medicare specialty | Nephrology |
Hospital affiliations
- Adventist Health SonoraSonora, CA
- Doctors Medical CenterModesto, CA
- Emanuel Medical CenterTurlock, CA
- Memorial Medical CenterModesto, CA
Other facilities
- Davita Archway Dialysis of ModestoDialysis facility · Modesto, CA
- Davita Ceres Dialysis CenterDialysis facility · Ceres, CA
- Shc Central ModestoDialysis facility · Modesto, CA
- Shc SonoraDialysis facility · Jamestown, CA
- Usrc ParkwayDialysis facility · Modesto, CA
Industry payments (Open Payments)
None reported for 2025 or 2024.
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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