Quick answers
- Does Michael P. O Leary accept Medicare assignment?
- Yes. Medicare's clinician data says Michael P. O Leary 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 Michael P. O Leary see?
- In 2024, CMS data shows 74 Original Medicare patients and 179 services for Michael P. O Leary. This counts Original Medicare only and measures volume, not quality.
- What is Michael P. O Leary's NPI number?
- 1811244312. 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 Michael P. O Leary, 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 | 74 |
|---|---|
| Services billed to Medicare | 179 |
| Different services or procedures | 58 |
| Participating Medicare provider | Yes |
| Average age of these patients | 73 |
Most frequent services
- Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)41 services
- New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more (99205)14 services
- Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)14 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 blood pressure69%
- High cholesterol69%
- Diabetes41%
- Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)39%
- Arthritis35%
- Ischemic heart disease24%
Hospitals where Michael P. O Leary works
Medicare's Facility Affiliation Data lists Michael P. O Leary at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- UCI Health-OrangeOrange, CA · Acute Care Hospital · Medicare rating: 4 of 5 stars · Emergency services: listed by Medicare · CCN 050348
Practice locations
Addresses where Michael P. O Leary is enrolled with Medicare (CMS data updated October 2, 2026).
- 101 the City Dr SOrange, CA 92868 (714) 634‑5549
Group practices
Medicare enrollment lists Michael P. O Leary as a member of this group (CMS data updated October 2, 2026).
- University Surgeons of Orange a Medical Group116 clinicians in the group
Specialties
- Surgical Oncologyprimary
- General Surgeryalso
Other surgical oncologists in Orange
Clinicians with the same Medicare primary specialty in Orange, CA — not a recommendation.
Other clinicians in University Surgeons of Orange a Medical Group
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of California, Irvine, California College Of Medicine |
| Graduation year | 2012 (14 years since medical school) |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1811244312 |
| 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- 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