Quick answers
- Does Ryan K. Onishi accept Medicare assignment?
- Yes. Medicare's clinician data says Ryan K. Onishi accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- How many Medicare patients does Ryan K. Onishi see?
- In 2024, CMS data shows 188 Original Medicare patients and 446 services for Ryan K. Onishi. This counts Original Medicare only and measures volume, not quality.
- What is Ryan K. Onishi's NPI number?
- 1053487116. 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 Ryan K. Onishi, 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 | 188 |
|---|---|
| Services billed to Medicare | 446 |
| Different services or procedures | 17 |
| Participating Medicare provider | Yes |
| Average age of these patients | 75 |
Most frequent services
- Photography of the retina (92250)85 services
- Established patient complete exam of visual system (92014)83 services
- New patient complete exam of visual system (92004)51 services
- Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)50 services
- Exam of visual field with extended testing (92083)46 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 pressure64%
- Arthritis42%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)21%
- Diabetes20%
- Chronic kidney disease20%
Practice locations
Addresses where Ryan K. Onishi is enrolled with Medicare (CMS data updated October 2, 2026).
- 31401 Rancho Viejo Rd, Suite 103San Juan Capistrano, CA 92675 (949) 496‑0552
Specialties
- Optometryprimary
Other optometrists in San Juan Capistrano
Clinicians with the same Medicare primary specialty in San Juan Capistrano, CA — not a recommendation.
Clinician information
| Credential | OD |
|---|---|
| Optometry school | Southern California College Of Optometry |
| Graduation year | 2000 (26 years since optometry school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1053487116 |
| 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