John Sic-Yiu Liu
Optometrist · Castro Valley, CA
John Sic-Yiu Liu is an optometrist with a practice address in Castro Valley, California, and NPI 1114949419, issued on Jul 24, 2006. Check the license (California 6498T, as entered in NPPES) with the California board that licenses this profession; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- John Sic-Yiu Liu
- Primary taxonomy
- Optometrist 152W00000X
- License number
- 6498T CA
Self-reported in NPPES; status is on the state search - Practice location
- 3550 Castro Valley Blvd, Castro Valley, CA 94546
- Phone
- (510) 581-1680
- Enumerated
- Jul 24, 2006
- Record last updated
- Jun 16, 2009 (not updated in 17 years: call before relying on the address or phone)
- Fax
- (510) 581-5070
- Medicaid ID
- SD0064980 CA
- Entity
- Type 1 · individual
8 nearest optometrist records → All 8,308 in California → Look up another NPI →
Also registered at 3550 Castro Valley Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Kaiyun Mai, O.D.Optometrist1730436643
- Mary Nguyen, O.D.Optometrist1285981274
Verify John Sic-Yiu Liu in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 6498TCheck the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
John Sic-Yiu Liu among 8,308 optometrist records in California
John Sic-Yiu Liu is one of 8,308 optometrist records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2006, is newer than 6% of them.
- NPI issued2006 · 6% of these records are older, 66% newer
- In a Medicare fileNo · 67% of these records are
- In the CMS Doctors and Clinicians fileNo · 43% of these records are
- Record last updated2009 · 67% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 152W00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
24 optometrist records list a practice address in Castro Valley
They are 24 of the 999 NPPES records with a practice address in Castro Valley, and 8,308 optometrist records in California. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 8,308 in California → Every provider in Castro Valley → Optometrist nationwide →
The 8 optometrist records with the nearest ZIP codes
- Christina Atkinson, O.D.Castro Valley, CA 945461619981792
- Marc Dea, ODCastro Valley, CA 945461174592646
- Sampson Fong, O. D.Castro Valley, CA 945461396861522
- Stella Levin, O.D.Castro Valley, CA 945461235197138
- Yuanbing Liao, O.D.Castro Valley, CA 945461497060875
- Kaiyun Mai, O.D.Castro Valley, CA 945461730436643
- John Nelson, O.D.Castro Valley, CA 945461922095082
- Mary Nguyen, O.D.Castro Valley, CA 945461285981274
Common questions
What is John Sic-Yiu Liu's NPI number?
John Sic-Yiu Liu's National Provider Identifier (NPI) is 1114949419, issued on Jul 24, 2006. An NPI identifies a provider in billing; it is not a license.
Where is John Sic-Yiu Liu located?
The NPPES record lists a practice address at 3550 Castro Valley Blvd, Castro Valley, CA, 94546. Phone: (510) 581-1680. Providers update this record themselves, so call before visiting.
How can I verify John Sic-Yiu Liu's license?
NPPES lists California license number 6498T, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.