Doctor profile · Federal record

Dr. Mary Fitzsimons, M.D

Emergency Medicine Physician (CMS: Emergency Medicine) · Antioch, CA

  • NPI 1053330431
  • Accepts Medicare
  • MIPS 86.3 / 100 · 2023
  • 45 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
3901 Lone Tree Way
Antioch, CA 945096200
(925) 779-7273
Mailing address
2100 Powell St, Ste 900
Emeryville, CA 946081826

Credentials & registration

NPPES · NUCC
NPI registered
July 2006 — 20 yrs on file
Profile last updated
October 24, 2007
Year of graduation
1981 — 45 yrs since
Specialty taxonomy
207P00000X — NUCC code
State license (1)
California #G56339
Medicaid
CA #00G563390

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1053330431. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
858
Distinct HCPCS
5
Medicare allowed
$105,221
HCPCS Description Services Patients Avg allowed
93010 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 303 272 $9
99285 Emergency department visit with high level of medical decision making 236 226 $188
99284 Emergency department visit with moderate level of medical decision making 134 126 $130
99291 Critical care, first 30-74 minutes 116 110 $234
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 69 66 $194

In context: peer comparison

Among 7 peers in this city , average services per provider: 118. This provider delivers 7.3× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
194
Patients
191
Total drug cost
$1,309
Drug Type Claims Patients Total cost
Ondansetron Hcl Generic 55 53 $323
Cephalexin Generic 46 46 $503
Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) Brand 45 45 $264
Prednisone Generic 21 20 $96
Ibuprofen Generic 16 16 $67
Azithromycin Generic 11 11 $56

Frequently asked questions

Auto-generated from federal data
What is Dr. Mary Fitzsimons's medical specialty?
Dr. Mary Fitzsimons practices Emergency Medicine Physician in Antioch, CA.
Where does Dr. Mary Fitzsimons practice?
Dr. Mary Fitzsimons practices at 3901 Lone Tree Way, Antioch, CA 945096200. Office phone: 9257797273.
What is Dr. Mary Fitzsimons's NPI?
Dr. Mary Fitzsimons's National Provider Identifier (NPI) is 1053330431, issued by NPPES.
Does Dr. Mary Fitzsimons accept Medicare assignment?
Yes. Dr. Mary Fitzsimons accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mary Fitzsimons commonly perform?
Top Medicare-reported procedures in 2023: Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (HCPCS 93010); Emergency department visit with high level of medical decision making (HCPCS 99285); Emergency department visit with moderate level of medical decision making (HCPCS 99284). Source: CMS Medicare Physician & Other Practitioners file.