Mary Fitzsimons, M.D
NPI 1053330431 · Emergency Medicine Physician · Antioch, CA
Enrolled with Medicare as Practitioner - Emergency Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mary Fitzsimons, M.D is a Emergency Medicine Physician provider in Antioch, CA (NPI 1053330431).
Provider details
- NPI number
- 1053330431
- Entity type
- Individual
- Primary specialty
- Emergency Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D
- Sex
- Female
- Sole proprietor
- No
- License
- G56339 (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
775 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) |
|---|---|---|
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report Only93010 | 271 | $9 |
| Emergency Department Visit With High Level of Medical Decision Making99285 | 239 | $194 |
| Emergency Department Visit With Moderate Level of Medical Decision Making99284 | 102 | $134 |
| Critical Care, First 30-74 Minutes99291 | 96 | $242 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 45 | $202 |
| Critical Care, Each Additional 30 Minutes99292 | 22 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 8 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Ondansetron Hcl | 52 | 51 |
| Hydrocodone/Acetaminophenbrand: Hydrocodone-Acetaminophen | 37 | 37 |
| Cephalexin | 28 | 28 |
| Prednisone | 17 | 17 |
| Doxycycline Monohydrate | 15 | 15 |
| Ibuprofen | 15 | 15 |
| Dicyclomine Hcl | 11 | 11 |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-07-18
- Last updated
- 2007-10-24
Frequently asked questions
- What is Mary Fitzsimons's NPI number?
- Mary Fitzsimons's National Provider Identifier (NPI) is 1053330431, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Fitzsimons's specialty?
- Mary Fitzsimons is listed in the NPPES registry with a primary specialty of Emergency Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Mary Fitzsimons located?
- Mary Fitzsimons's practice location on file with NPPES is 3901 Lone Tree Way, Antioch, CA 94509-6200.
- What is Mary Fitzsimons's phone number?
- The practice phone number listed in the NPPES registry for Mary Fitzsimons is (925) 779-7273.
- Does Mary Fitzsimons accept Medicare?
- Mary Fitzsimons is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mary Fitzsimons's NPI active?
- Yes — Mary Fitzsimons's NPI (1053330431) is active in the NPPES registry as of the last update on 2007-10-24.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.