Zareth Irwin, MD
NPI 1912031139 · Emergency Medicine Physician · Orange, CA
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Zareth Irwin, MD is a Emergency Medicine Physician provider in Orange, CA (NPI 1912031139).
Provider details
- NPI number
- 1912031139
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- A95363 (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
19 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
224 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) |
|---|---|---|
| Emergency Department Visit With High Level of Medical Decision Making99285 | 101 | $170 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report Only93010 | 59 | $8 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 34 | $118 |
| Critical Care, First 30-74 Minutes99291 | 16 | $209 |
| X-Ray of Chest, 1 View71045 | 14 | $8 |
Typical Medicare-allowed amounts for these services range $8–$209 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-03-16
- Last updated
- 2007-07-08
Frequently asked questions
- What is Zareth Irwin's NPI number?
- Zareth Irwin's National Provider Identifier (NPI) is 1912031139, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Zareth Irwin's specialty?
- Zareth Irwin is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Zareth Irwin located?
- Zareth Irwin's practice location on file with NPPES is 101 the City Dr S, Orange, CA 92868-3201.
- What is Zareth Irwin's phone number?
- The practice phone number listed in the NPPES registry for Zareth Irwin is (714) 456-8068.
- Does Zareth Irwin accept Medicare?
- Zareth Irwin is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Zareth Irwin's NPI active?
- Yes — Zareth Irwin's NPI (1912031139) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.