Walailuk Chaiyarat, MD
NPI 1811140478ActiveIndividual· Internal Medicine, Hematology & Oncology· Concord, CA
Internal Medicine, Hematology & Oncology (MD) with John Muir Physician Network, practicing in Concord, California. In 2024 Medicare paid $1,580,830 for 507 patients, and Part D covered 1,756 of their prescriptions, 81% of them generic. Novartis Pharmaceuticals Corporation was the largest of 39 companies reporting payments in 2025, $3,730 in all, mostly food and beverage. Lists John Muir Medical Center - Concord Campus and 4 other hospitals as hospital affiliations.
Overview
| NPI | 1811140478 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | Yes |
| NPI issued | Oct 28, 2008 |
| Last updated in NPPES | Jun 11, 2019 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Hematology & Oncology Primary | 207RH0003X | A117301 | 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 - Hematology/Oncology (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 507 |
|---|---|
| Services billed | 132,943 across 108 procedure codes |
| Paid by Medicare | $1,580,830 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,756 · 3,315 30-day fills |
|---|---|
| Patients | 320 |
| Total drug cost | $2,163,830 |
| Generic share | 81% of claims |
Education and affiliations
| Graduation year | 2000 |
|---|---|
| Medicare specialty | Hematology/Oncology |
| Telehealth | Offers telehealth |
Medical group
- John Muir Physician NetworkPleasant Hill, CA · 494 clinicians
Hospital affiliations
- John Muir Medical Center - Concord CampusConcord, CA
- John Muir Medical Center - Walnut Creek CampusWalnut Creek, CA
- Providence Queen of the Valley Medical CenterNapa, CA
- Sutter Medical Center, SacramentoSacramento, CA
- Sutter Solano Medical CenterVallejo, CA
Other facilities
- John Muir Home Health ServicesHome health agency · Concord, CA
- Mare Island Home Health IncHome health agency · Fairfield, CA
Industry payments (Open Payments)
- 2025$3,730 · 136 payments from 39 companies
- 2024$2,569 · 118 payments from 32 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Novartis Pharmaceuticals Corporation | $784.93 | 15 |
| Astrazeneca Pharmaceuticals LP | $381.54 | 17 |
| Janssen Biotech, Inc. | $277.55 | 11 |
| Merck Sharp & Dohme LLC | $236.08 | 9 |
| Celgene Corporation | $187.20 | 10 |
What the 2025 payments were for
- Food and Beverage$3,010 · 128 payments
- Long term medical supply or device loan$598.20 · 6 payments
- Education$121.72 · 2 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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