Mark C. O'Brien, D.O.
NPI 1497744247ActiveIndividual· Internal Medicine· Vista, CA
Internal Medicine (D.O.) in Vista, California, trained at Michigan State University College of Osteopathic Medicine (class of 1987). In 2024 Medicare paid $59,450 for 184 patients, and Part D covered 160 of their prescriptions, 87% of them generic. Edwards Lifesciences Corporation was the largest of 7 companies reporting payments in 2025, $380.21 in all, mostly food and beverage.
Overview
| NPI | 1497744247 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | D.O. |
| Sole proprietor | No |
| NPI issued | Oct 14, 2005 |
| Last updated in NPPES | Apr 1, 2025 |
| Certified by provider | Apr 1, 2025 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | 20A6017 | CA |
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 (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 184 |
|---|---|
| Services billed | 689 across 11 procedure codes |
| Paid by Medicare | $59,450 |
Part D prescriptions in 2024
| Prescriptions (claims) | 160 · 166 30-day fills |
|---|---|
| Patients | 93 |
| Total drug cost | $9,246 |
| Generic share | 87% of claims |
Education and affiliations
| Medical school | Michigan State University College of Osteopathic Medicine |
|---|---|
| Graduation year | 1987 |
| Medicare specialty | Internal Medicine |
| Telehealth | Offers telehealth |
Industry payments (Open Payments)
- 2025$380.21 · 9 payments from 7 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Edwards Lifesciences Corporation | $172.50 | 1 |
| Exact Sciences Corporation | $48.30 | 2 |
| Novo Nordisk Inc | $46.43 | 2 |
| Inspire Medical Systems, Inc. | $36.83 | 1 |
| Lilly USA, LLC | $29.36 | 1 |
What the 2025 payments were for
- Food and Beverage$380.21 · 9 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 57 internal medicine physicians in Vista · All internal medicine physicians in California