Edmund Co Yao, M.D.
NPI 1245328004ActiveIndividual· Internal Medicine· Stockton, CA
Internal Medicine (M.D.) with Inpatient Specialists of California PC, practicing in Stockton, California. Their prescriptions cost Medicare Part D more than their services did: $3,178,800 for 37,834 claims, against $255,714 paid for services in 2024. Bayer Healthcare Pharmaceuticals Inc. was the largest of 5 companies reporting payments in 2025, $117.83 in all, mostly food and beverage. Lists Adventist Health Lodi Memorial and 4 other hospitals as hospital affiliations.
Overview
| NPI | 1245328004 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Oct 10, 2006 |
| Last updated in NPPES | Dec 30, 2019 |
| Certified by provider | Dec 30, 2019 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine Primary | 207R00000X | A84312 | 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 | 1,302 |
|---|---|
| Services billed | 2,936 across 22 procedure codes |
| Paid by Medicare | $255,714 |
Part D prescriptions in 2024
| Prescriptions (claims) | 37,834 · 49,380 30-day fills |
|---|---|
| Patients | 1,320 |
| Total drug cost | $3,178,800 |
| Generic share | 83% of claims |
Education and affiliations
| Graduation year | 1991 |
|---|---|
| Medicare specialty | Internal Medicine |
| Secondary specialties | General Practice |
Medical group
- Inpatient Specialists of California PCOakdale, CA · 385 clinicians
Hospital affiliations
- Adventist Health Lodi MemorialLodi, CA
- Mark Twain Medical CenterSan Andreas, CA
- San Joaquin General HospitalFrench Camp, CA
- St Joseph's Medical Center of StocktonStockton, CA
- Sutter Amador HospitalJackson, CA
Other facilities
- Emerald Health and WellnessHome health agency · Stockton, CA
- Holistic Approach IncHome health agency · Stockton, CA
- Lorian HealthHome health agency · Elk Grove, CA
- Sky Healthcare Home Health ServicesHome health agency · Pleasanton, CA
- Tri-Valley Home Health Care, IncHome health agency · Stockton, CA
- Lincoln Square Post Acute CareNursing home · Stockton, CA
Industry payments (Open Payments)
- 2025$117.83 · 7 payments from 5 companies
- 2024$106.09 · 6 payments from 3 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Bayer Healthcare Pharmaceuticals Inc. | $61.44 | 3 |
| Boehringer Ingelheim Pharmaceuticals, Inc. | $15.18 | 1 |
| Pfizer Inc. | $14.01 | 1 |
| Abbvie Inc. | $13.65 | 1 |
| Corcept Therapeutics | $13.55 | 1 |
What the 2025 payments were for
- Food and Beverage$117.83 · 7 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 117 internal medicine physicians in Stockton · All internal medicine physicians in California