William G Ong, MD - Medicare Pediatrics in Livermore, CA

William G Ong, MD is a medicare enrolled "Pediatrics" physician in Livermore, California. His current practice location is 3000 Las Positas Rd, Livermore, California. You can reach out to his office (for appointments etc.) via phone at (925) 243-2600.

William G Ong is licensed to practice in California (license number A82738) and he also participates in the medicare program. He does not accept medicare assignments directly but he may accept medicare through third-party (refer to Reassignment section below) and may also prescribe medicare part D drugs. His NPI Number is 1508944604.

Contact Information

William G Ong, MD
3000 Las Positas Rd,
Livermore, CA 94551-9627
(925) 243-2600
Not Available

Map and Direction




Physician's Profile

Full NameWilliam G Ong
GenderMale
SpecialityPediatrics
Location3000 Las Positas Rd, Livermore, California
Accepts Medicare AssignmentsMedicare enrolled and may accept medicare through third-party reassignment. May prescribe medicare part D drugs.
  NPI Data:
  • NPI Number: 1508944604
  • Provider Enumeration Date: 11/02/2006
  • Last Update Date: 12/13/2021
  Medicare PECOS Information:
  • PECOS PAC ID: 1153382536
  • Enrollment ID: I20041019001275

Medical Identifiers

Medical identifiers for William G Ong such as npi, medicare ID, medicare PIN, medicaid, etc.
IdentifierTypeStateIssuer
1508944604NPI-NPPES
00A827380MedicaidCA

Medical Taxonomies and Licenses

TaxonomyTypeLicense (State)Status
208000000XPediatrics A82738 (California)Primary

Medicare Reassignments

Some practitioners may not bill the customers directly but medicare billing happens through clinics / group practice / hospitals where the provider works. Medicare reassignment of benefits is a mechanism by which practitioners allow third parties to bill and receive payment for medicare services performed by them. William G Ong allows following entities to bill medicare on his behalf.
Entity NamePermanente Medical Group Inc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1073606299
PECOS PAC ID: 8921910225
Enrollment ID: O20031104000710

Medicare Part D Prescriber Enrollment

Any physician or other eligible professional who prescribes Part D drugs must either enroll in the Medicare program or opt out in order to prescribe drugs to their patients with Part D prescription drug benefit plans. William G Ong is enrolled with medicare and thus, if eligible, can prescribe medicare part D drugs to patients with medicare part D benefits.

Mailing Address and Practice Location

Mailing AddressPractice Location Address
William G Ong, MD
1800 Harrison St Fl 7,
Oakland, CA 94612-3466

Ph: (510) 625-6262
William G Ong, MD
3000 Las Positas Rd,
Livermore, CA 94551-9627

Ph: (925) 243-2600

Reviews and Comments


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Medicare Program: Medicare is a federal government program which provides health insurance to people who are 65 or older. This program also covers certain younger people with disabilities (who receive Social Security Disability Insurance - SSDI), and people with End-Stage Renal Disease (permanent kidney failure requiring dialysis or a transplant, sometimes called ESRD.

Medicare Assignment: Assignment means that your doctor, provider, or supplier agrees (or is required by law) to accept the Medicare-approved amount as full payment for covered services. Most doctors, providers, and suppliers accept assignment, but you should always check to make sure. Participating providers have signed an agreement to accept assignment for all Medicare-covered services.

NPI Number: The National Provider Identifier (NPI) is a unique identification number for covered health care providers. The NPI must be used in lieu of legacy provider identifiers in the HIPAA standards transactions. Covered health care providers and all health plans and health care clearinghouses must use the NPIs in the administrative and financial transactions adopted under HIPAA (Health Insurance Portability and Accountability Act).

Our Data: Information on www.medicarelist.com is built using data sources published by Centers for Medicare & Medicaid Services (CMS) under Freedom of Information Act (FOIA). The information disclosed on the NPI Registry are FOIA-disclosable and are required to be disclosed under the FOIA and the eFOIA amendments to the FOIA. There is no way to 'opt out' or 'suppress' the NPPES record data for health care providers with active NPIs.