William G. Ong, MD
William G. Ong is a Pediatrics Physician provider (Pediatrics) practicing in Livermore, CA, registered in the NPPES registry with NPI 1508944604 since 2006. The credential MD stands for Doctor of Medicine. Practices at Kaiser Foundation Health Plan Inc (listed at the same practice address in NPPES).
✓ Active NPI ✓ Valid NPI checksum
| NPI | 1508944604 |
|---|---|
| Entity type | Individual (Type 1) |
| Name | William G. Ong |
| Credential | MD |
| Sex | Male |
| Practice address | 3000 LAS POSITAS RD, Livermore, CA, 94551 |
| Phone | 9252432600 |
| Enumeration date | 2006-11-02 |
| Last updated in NPPES | 2021-12-13 |
Taxonomy & licenses
| Taxonomy code | Specialty | Primary | License | State |
|---|---|---|---|---|
| 208000000X | Pediatrics Physician | Primary | A82738 | CA |
MD — Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential
Other identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| 00A827380 | Medicaid | CA | — |
Copy-ready billing details
Provider: William Ong, MD NPI: 1508944604 Taxonomy: 208000000X (Pediatrics Physician) Address: 3000 LAS POSITAS RD, Livermore, CA, 94551
Other providers at this practice address
| NPI | Name | Type | Specialty | Location |
|---|---|---|---|---|
| 1841372836 | Ian Bartos | Individual | Pediatrics Physician | Livermore, CA |
| 1588742647 | Sheri Morris | Individual | Internal Medicine Physician | Livermore, CA |
| 1518045673 | Iftekhar Sareshwala | Individual | Internal Medicine Physician | Livermore, CA |
| 1427136597 | Sharon Mowat | Individual | Pediatrics Physician | Livermore, CA |
| 1598843641 | Ryan Wu | Individual | Internal Medicine Physician | Livermore, CA |
| 1699853796 | Nancy Everett | Individual | Obstetrics & Gynecology Physician | Livermore, CA |
| 1134207236 | Andrew Rodgers | Individual | Internal Medicine Physician | Livermore, CA |
| 1952489049 | Joann Daley | Individual | Pediatrics Physician | Livermore, CA |
Verify this record
Cross-check NPI 1508944604 against the authoritative CMS record: view William G. Ong on the official NPPES registry .
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty. Read the full guide or validate an NPI number.
Frequently asked questions
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Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2021-12-13.