Doctor profile · Federal record

Dr. William Gregory, MD

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

  • NPI 1659337350
  • Accepts Medicare
  • 27 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
100 W California Blvd
Pasadena, CA 911053010
(626) 397-3445
fax (626) 397-5643
Mailing address
Po Box 60259
Los Angeles, CA 900600259

Credentials & registration

NPPES · NUCC
NPI registered
April 2006 — 20 yrs on file
Profile last updated
June 13, 2008
Year of graduation
1999 — 27 yrs since
Specialty taxonomy
207P00000X — NUCC code
State license (1)
California #A78714
Medicaid
CA #OOA787140

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1659337350. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
146
Distinct HCPCS
3
Medicare allowed
$17,826
HCPCS Description Services Patients Avg allowed
99284 Emergency department visit with moderate level of medical decision making 84 84 $120
99285 Emergency department visit with high level of medical decision making 44 43 $174
93010 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 18 16 $8

In context: peer comparison

Among 18 peers in this city , average services per provider: 68. This provider delivers 2.1× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
52
Patients
50
Total drug cost
$685
Drug Type Claims Patients Total cost
Prednisone Generic 21 21 $40
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 17 17 $249
Albuterol Sulfate Hfa (Albuterol Sulfate) Brand 14 12 $396

Frequently asked questions

Auto-generated from federal data
What is Dr. William Gregory's medical specialty?
Dr. William Gregory practices Emergency Medicine Physician in Pasadena, CA.
Where does Dr. William Gregory practice?
Dr. William Gregory practices at 100 W California Blvd, Pasadena, CA 911053010. Office phone: 6263973445.
What is Dr. William Gregory's NPI?
Dr. William Gregory's National Provider Identifier (NPI) is 1659337350, issued by NPPES.
Does Dr. William Gregory accept Medicare assignment?
Yes. Dr. William Gregory accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William Gregory commonly perform?
Top Medicare-reported procedures in 2023: Emergency department visit with moderate level of medical decision making (HCPCS 99284); Emergency department visit with high level of medical decision making (HCPCS 99285); Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (HCPCS 93010). Source: CMS Medicare Physician & Other Practitioners file.