Karen Simon, M.D.
NPI 1548384167ActiveIndividual· Internal Medicine, Gastroenterology· Oxnard, CA
Internal Medicine, Gastroenterology (M.D.) in Oxnard, California, trained at Northwestern University Feinberg Medical School (class of 2001). Their prescriptions cost Medicare Part D more than their services did: $558,887 for 732 claims, against $242,487 paid for services in 2024. Abbvie Inc. was the largest of 19 companies reporting payments in 2025, $1,742 in all, mostly food and beverage.
Overview
| NPI | 1548384167 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Mar 19, 2007 |
| Last updated in NPPES | Dec 9, 2015 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | A81831 | CA |
| Specialist | 174400000X | A81831 | CA |
| Internal Medicine | 207R00000X | A81831 | 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 4, 2026 | No match | — |
| New York OMIG · Nov 4, 2026 | No match | — |
| Ohio Medicaid · Nov 4, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 4, 2026 | No match | — |
| Washington HCA · Nov 4, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Gastroenterology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 727 |
|---|---|
| Services billed | 3,682 across 45 procedure codes |
| Paid by Medicare | $242,487 |
Part D prescriptions in 2024
| Prescriptions (claims) | 732 · 1,371 30-day fills |
|---|---|
| Patients | 196 |
| Total drug cost | $558,887 |
| Generic share | 81% of claims |
Education and affiliations
| Medical school | Northwestern University Feinberg Medical School |
|---|---|
| Graduation year | 2001 |
| Medicare specialty | Gastroenterology |
| Telehealth | Offers telehealth |
Medical group
- Genesis Healthcare Partners PCSan Francisco, CA · 228 clinicians
Hospital affiliation
- St Johns Regional Medical CenterOxnard, CA
Industry payments (Open Payments)
- 2025$1,742 · 77 payments from 19 companies
- 2024$2,144 · 92 payments from 18 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $396.05 | 29 |
| Madrigal Pharmaceuticals | $306.26 | 12 |
| Janssen Biotech, Inc. | $247.95 | 9 |
| Lilly USA, LLC | $152.95 | 7 |
| Phathom Pharmaceuticals, Inc. | $146.68 | 2 |
What the 2025 payments were for
- Food and Beverage$1,742 · 77 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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