Gregory Larsen, D.O.
NPI 1104073709 · Emergency Medicine Physician · Colton, CA
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Provider details
- NPI number
- 1104073709
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- D.O.
- Sex
- Male
- Sole proprietor
- No
- License
- 20A10521 (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
17 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
906 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 Moderate Level of Medical Decision Making99284 | 383 | $116 |
| Emergency Department Visit With High Level of Medical Decision Making99285 | 323 | $168 |
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report Only93010 | 109 | $8 |
| Emergency Department Visit With Low Level of Medical Decision Making99283 | 56 | $68 |
| Critical Care, First 30-74 Minutes99291 | 24 | $207 |
| Simple Repair of Surface Wound of Scalp, Neck, Underarms, Trunk, Arms, Or Legs, 2.6-7.5 Cm12002 | 11 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 13 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 48 | 46 |
| Prednisone | 44 | 42 |
| Cephalexin | 44 | 43 |
| Oxycodone Hcl/Acetaminophenbrand: Oxycodone-Acetaminophen | 25 | 23 |
| Azithromycin | 20 | 20 |
| Doxycycline Hyclate | 18 | 18 |
| Naproxen | 17 | 17 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2008-08-26
- Last updated
- 2009-10-30
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.