Gregory Simsarian, M.D
NPI 1144250713 · Emergency Medicine Physician · Laguna Hills, CA
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregory Simsarian, M.D is a Emergency Medicine Physician provider in Laguna Hills, CA (NPI 1144250713).
Provider details
- NPI number
- 1144250713
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D
- Sex
- Male
- Sole proprietor
- No
- License
- G65647 (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
442 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 | 316 | $185 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 114 | $128 |
| Emergency Department Visit With Low Level of Medical Decision Making99283 | 12 | $75 |
Typical Medicare-allowed amounts for these services range $75–$185 (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.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 4 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 20 | 20 |
| Oxycodone Hcl/Acetaminophenbrand: Oxycodone-Acetaminophen | 20 | 20 |
| Ondansetronbrand: Ondansetron Odt | 18 | 18 |
| Cephalexin | 14 | 14 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-07-03
- Last updated
- 2008-02-06
Frequently asked questions
- What is Gregory Simsarian's NPI number?
- Gregory Simsarian's National Provider Identifier (NPI) is 1144250713, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregory Simsarian's specialty?
- Gregory Simsarian is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Gregory Simsarian located?
- Gregory Simsarian's practice location on file with NPPES is 24451 Health Center Dr, Laguna Hills, CA 92653-3689.
- What is Gregory Simsarian's phone number?
- The practice phone number listed in the NPPES registry for Gregory Simsarian is (714) 837-4500.
- Does Gregory Simsarian accept Medicare?
- Gregory Simsarian is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregory Simsarian's NPI active?
- Yes — Gregory Simsarian's NPI (1144250713) is active in the NPPES registry as of the last update on 2008-02-06.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.