Gregory H. Shimizu, MD
NPI 1154492130ActiveIndividual· Internal Medicine· Fontana, CA
Internal Medicine (MD) in Fontana, California, trained at George Washington University School of Medicine (class of 1988). Mostly services rather than prescriptions: Medicare paid $73,576 for 243 patients in 2024, with only 29 Part D claims. Zoll Services LLC (A/K/A Zoll Lifecor Corp) reported $101.55 in payments in 2025, mostly food and beverage.
Overview
| NPI | 1154492130 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | No |
| NPI issued | Nov 13, 2006 |
| Last updated in NPPES | Sep 23, 2008 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | G67137 | 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 | 243 |
|---|---|
| Services billed | 944 across 8 procedure codes |
| Paid by Medicare | $73,576 |
Part D prescriptions in 2024
| Prescriptions (claims) | 29 · 30 30-day fills |
|---|---|
| Patients | 16 |
| Total drug cost | $1,795 |
| Generic share | 83% of claims |
Education and affiliations
| Medical school | George Washington University School of Medicine |
|---|---|
| Graduation year | 1988 |
| Medicare specialty | Internal Medicine |
Medical group
- Temecula Valley Hospitalist Medical Group IncTemecula, CA · 29 clinicians
Hospital affiliation
- Temecula Valley HospitalTemecula, CA
Industry payments (Open Payments)
- 2025$101.55 · 1 payment from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Zoll Services LLC (A/K/A Zoll Lifecor Corp) | $101.55 | 1 |
What the 2025 payments were for
- Food and Beverage$101.55 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 118 internal medicine physicians in Fontana · All internal medicine physicians in California