Liam Ghiam, MD, MS
Radiation Oncology Physician · Los Alamitos, CA
Liam Ghiam, MD, MS is a radiation oncology physician with a practice address in Los Alamitos, California, and NPI 1689123879, issued on Sep 28, 2016. Check the license (California A165739, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Liam Ghiam
- Credential
- MD, MS
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License number
- A165739 CA
Self-reported in NPPES; status is on the state search - Practice location
- 3951 Katella Ave Ste 102, Los Alamitos, CA 90720
- Phone
- (562) 799-3198
- Enumerated
- Sep 28, 2016
- Record last updated
- Jul 10, 2025
- Fax
- (562) 799-3509
- Medicare enrollment
- Enrolled (PECOS I20200210002780); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 735 in California → Look up another NPI →
Verify Liam Ghiam in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A165739Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
19% more Medicare Part D claims than the average radiation oncology physician in 2024
160 Medicare Part D claims for 74 beneficiaries, against an average of 134 among the 4,851 providers of this specialty who prescribed in Part D. Brand-name drugs were 19% of claims. 19 claims were for opioids.
Most prescribed
- Gabapentin26 claims
- Ssd24 claims
- Tamsulosin Hcl23 claims
- Bicalutamide13 claims
- Hydrocodone-Acetaminophen13 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- UC Regents Department OF Radiation OncologyOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Liam Ghiam among 735 radiation oncology physician records in California
Liam Ghiam, MD, MS is one of 735 radiation oncology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2016, is newer than 84% of them.
- NPI issued2016 · 84% of these records are older, 13% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 74% of these records are
- Graduated2003 · median 2005 among the 545 with a school on file
- Record last updated2025 · 55% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in California
There are 735 radiation oncology physician records in California.
All 735 in California → Every provider in Los Alamitos → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Abhishek Kumar, MDCerritos, CA 907031043847114
- John Thropay, M.D.Montebello, CA 906401427128073
- Alam Syed, M.D.Long Beach, CA 908011316956279
- Sulabha Dave, MDLong Beach, CA 908051821191446
- Jessica Xing, MDLong Beach, CA 908051689133548
- Christine YangLong Beach, CA 908061699351288
- Thomas Gates, MDLong Beach, CA 908131023072915
- Sayana Shah, M.D.Long Beach, CA 908131972793917
Common questions
What is Liam Ghiam, MD, MS's NPI number?
Liam Ghiam, MD, MS's National Provider Identifier (NPI) is 1689123879, issued on Sep 28, 2016. An NPI identifies a provider in billing; it is not a license.
Where is Liam Ghiam, MD, MS located?
The NPPES record lists a practice address at 3951 Katella Ave Ste 102, Los Alamitos, CA, 90720. Phone: (562) 799-3198. Providers update this record themselves, so call before visiting.
How can I verify Liam Ghiam, MD, MS's license?
NPPES lists California license number A165739, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Liam Ghiam, MD, MS prescribe under Medicare Part D?
In 2024, Liam Ghiam, MD, MS had 160 Medicare Part D claims for 74 beneficiaries; the average among radiation oncology physician prescribers was 134. Part D covers Medicare prescriptions 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. Medicare files from data.cms.gov. 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.