Liam Ghiam, MD, MS
NPI 1689123879 · Radiation Oncology Physician · Los Alamitos, CA
Enrolled with Medicare as Practitioner - Radiation Oncology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Liam Ghiam, MD, MS is a Radiation Oncology Physician provider in Los Alamitos, CA (NPI 1689123879).
Provider details
- NPI number
- 1689123879
- Entity type
- Individual
- Primary specialty
- Radiation Oncology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD, MS
- Sex
- Male
- Sole proprietor
- No
- License
- A165739 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
9 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
2,468 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Stereoscopic X-Ray Guidance for Localization of Target Volume for the Delivery of Radiation TherapyG6002 | 1,300 | $20 |
| Radiation Treatment Management, 5 Treatment Sessions77427 | 296 | $190 |
| Calculation of Radiation Therapy Dose77300 | 222 | $32 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 130 | $142 |
| Design and Construction of Complex Radiation Treatment Device77334 | 126 | $59 |
| Complex Radiation Therapy Planning77263 | 76 | $166 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Gabapentin | 26 | — |
| Silver Sulfadiazinebrand: Ssd | 24 | 18 |
| Tamsulosin Hcl | 23 | — |
| Bicalutamide | 13 | 13 |
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 13 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means , never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2016-09-28
- Last updated
- 2025-07-10
- Certified
- 2025-07-10
Frequently asked questions
- What is Liam Ghiam's NPI number?
- Liam Ghiam's National Provider Identifier (NPI) is 1689123879, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Liam Ghiam's specialty?
- Liam Ghiam is listed in the NPPES registry with a primary specialty of Radiation Oncology Physician (Allopathic & Osteopathic Physicians).
- Where is Liam Ghiam located?
- Liam Ghiam's practice location on file with NPPES is 3951 Katella Ave Ste 102, Los Alamitos, CA 90720-3303.
- What is Liam Ghiam's phone number?
- The practice phone number listed in the NPPES registry for Liam Ghiam is (562) 799-3198.
- Does Liam Ghiam accept Medicare?
- Liam Ghiam is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Liam Ghiam's NPI active?
- Yes — Liam Ghiam's NPI (1689123879) is active in the NPPES registry as of the last update on 2025-07-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.