Quick answers
- Does Otto Y. Liao accept Medicare assignment?
- Medicare's clinician data says Otto Y. Liao may accept Medicare assignment (as of October 2, 2026). Ask the office whether they accept it for your visit.
- How many Medicare patients does Otto Y. Liao see?
- In 2024, CMS data shows 232 Original Medicare patients and 11,569 services for Otto Y. Liao. This counts Original Medicare only and measures volume, not quality.
- What is Otto Y. Liao's NPI number?
- 1225042674. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Medicare activity in 2024
Official CMS public-use data for Otto Y. Liao, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.
| Original Medicare patients | 232 |
|---|---|
| Services billed to Medicare | 11,569 |
| Different services or procedures | 12 |
| Participating Medicare provider | Yes |
| Average age of these patients | 76 |
Most frequent services
- Professional service for preparation and provision of 1 or more antigens (95165)6,175 services
- Test for allergy using allergenic extract (95004)3,270 services
- Professional service for multiple injections of allergen (95117)1,528 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)198 services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)79 services
Chronic conditions among these patients
Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).
- High cholesterol75%
- High blood pressure70%
- Arthritis53%
- Asthma29%
- Diabetes25%
- Osteoporosis24%
Practice locations
Addresses where Otto Y. Liao is enrolled with Medicare (CMS data updated October 2, 2026).
- 1076 E 1st St, Suite BTustin, CA 92780 (714) 838‑2617
Specialties
- Allergy/Immunologyprimary
- Internal Medicinealso
- Pediatric Medicinealso
Other allergist and immunologists in California
Clinicians with the same Medicare primary specialty in California — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Graduation year | 1997 (29 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1225042674 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians