Provider Profile
Zachary G. O'Leary, PA-C
Unclaimed ProfileAbout Zachary O'leary
Zachary G. O'Leary, PA-C is a physician assistant practicing in Castro Valley, CA. Zachary trained at Stanford University School of Medicine, graduating in 2021. According to Medicare claims data, Zachary cared for 201 Medicare patients across 256 services. The services billed most often include established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more, established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more, and established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more. This provider record is associated with NPI 1083298178.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (888) 924-1036
- Email not available
Practice Locations
20642 JOHN DR
Castro Valley, CA 94546
5189 Hospital Rd
Mariposa, CA 95338
Procedures Most Often Billed to Medicare
256 services · 201 patients · 6 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Sarscov2 vac 50 mcg/0.5ml im | Treatment | 91322 |
13 | Less often than most peers in Physician Assistant |
| Admn sarscov2 vacc 1 dose | Treatment | 90480 |
13 | Less often than most peers in Physician Assistant |
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
82 | As often as other peers in Physician Assistant |
| Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more | Office visit | 99215 |
60 | More often than most peers in Physician Assistant |
| Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | Office visit | 99213 |
56 | As often as other peers in Physician Assistant |
| Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient' | Billing code | G2211 |
32 | Less often than most peers in Physician Assistant |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other physician assistants at this location 6
Same specialty, same street address — most likely the same department or group.
Related specialists at this location 6
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
More connections — 31 related providers in 4 groups
Other physician assistants in Castro Valley 7
Same specialty, same city.
Trained at Stanford University School of Medicine 8
Other providers in the same specialty who trained at the same institution.
Class of 2021 at Stanford University School of Medicine 8
Providers who graduated from the same medical school in the same year.
Also performs Sarscov2 vac 50 mcg/0.5ml im 8
Providers in CA who bill this service to Medicare most often.
Common questions
What kind of doctor is Zachary G. O'Leary?
Zachary G. O'Leary is a physician assistant in Castro Valley, CA. That is the designation recorded for this NPI in the federal registry.
NPI registry
What is Zachary G. O'Leary's address?
Zachary G. O'Leary is listed at 20642 John Dr, Castro Valley, CA 94546. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How can I make an appointment with Zachary G. O'Leary?
The number on file is (888) 924-1036. Contact the office directly to confirm availability and scheduling.
NPI registry
What is Zachary G. O'Leary's NPI number?
Zachary G. O'Leary's National Provider Identifier is 1083298178. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Where did Zachary G. O'Leary train?
Zachary G. O'Leary attended Stanford University School of Medicine, graduating in 2021. This comes from the CMS National Downloadable File.
CMS public data
How long has Zachary G. O'Leary been practicing?
Zachary G. O'Leary has 5 years experience. Calculated from a graduation year of 2021, reported in the CMS National Downloadable File.
CMS public data
What procedures does Zachary G. O'Leary perform?
According to Medicare billing data, Zachary G. O'Leary provides treatments such as sarscov2 vac 50 mcg/0.5ml im and admn sarscov2 vacc 1 dose, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Has Zachary G. O'Leary confirmed this information?
Not yet. This profile is built from public federal data and has not been confirmed by Zachary G. O'Leary. If this is you, claiming it is free.
Guide.md
Guide.md listings do not constitute medical advice or an endorsement.