Doctor profile · Federal record
Dr. Mary Ann Trephan, MD
Emergency Medicine Physician (CMS: Emergency Medicine) · Northridge, CA
- NPI 1891752614
- Accepts Medicare
- 33 yrs in practice
- Female
- Solo practice
- No sanctions
Practice & contact
- Primary practice
-
18300 Roscoe Blvd
Northridge, CA 91328
(818) 885-8500 - Mailing address
-
Po Box 4675
Thousand Oaks, CA 913591675
Credentials & registration
- NPI registered
- April 2006 — 20 yrs on file
- Profile last updated
- December 1, 2021
- Year of graduation
- 1993 — 33 yrs since
- Specialty taxonomy
- 207P00000X — NUCC code
- State license (1)
- California #G85040
- Medicaid
- CA #00G850400
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1891752614. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
793
Distinct HCPCS
10
Medicare allowed
$69,129
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 253 | 225 | $137 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 113 | 113 | $177 | |
81001 |
Manual urinalysis test with examination using microscope, automated | 81 | 72 | $3 | |
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 67 | 63 | $97 | |
87804 |
Detection test by immunoassay with direct visual observation for influenza virus | 51 | 26 | $16 | |
71046 |
X-ray of chest, 2 views | 49 | 49 | $38 | |
87426 |
Detection test by immunoassay technique for severe acute respiratory syndrome coronavirus | 34 | 33 | $35 | |
36415 |
Insertion of needle into vein for collection of blood sample | 29 | 28 | $8 | |
80053 |
Blood test, comprehensive group of blood chemicals | 29 | 28 | $10 | |
85025 |
Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count | 29 | 28 | $8 |
In context: peer comparison
Among 6 peers in this city , average services per provider: 112. This provider delivers 7.1× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
290
Patients
283
Total drug cost
$3,828
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Cephalexin | Generic | 71 | 67 | $670 |
| Azithromycin | Generic | 61 | 60 | $271 |
| Albuterol Sulfate Hfa (Albuterol Sulfate) | Brand | 38 | 38 | $1,087 |
| Prednisone | Generic | 32 | 32 | $71 |
| Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) | Brand | 22 | 22 | $211 |
| Moxifloxacin (Moxifloxacin Hcl) | Brand | 17 | 16 | $451 |
| Ciprofloxacin Hcl | Generic | 15 | 14 | $116 |
| Mupirocin | Generic | 12 | 12 | $127 |
| Neomycin-Polymyxin-Hc (Neomycin/Polymyxin B/Hydrocort) | Brand | 11 | 11 | $695 |
| Paxlovid (Eua) (Nirmatrelvir/Ritonavir) | Brand | 11 | 11 | $129 |
Frequently asked questions
What is Dr. Mary Ann Trephan's medical specialty?
Dr. Mary Ann Trephan practices Emergency Medicine Physician in Northridge, CA.
Where does Dr. Mary Ann Trephan practice?
Dr. Mary Ann Trephan practices at 18300 Roscoe Blvd, Northridge, CA 91328. Office phone: 8188858500.
What is Dr. Mary Ann Trephan's NPI?
Dr. Mary Ann Trephan's National Provider Identifier (NPI) is 1891752614, issued by NPPES.
Does Dr. Mary Ann Trephan accept Medicare assignment?
Yes. Dr. Mary Ann Trephan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mary Ann Trephan commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); New patient office or other outpatient visit (HCPCS 99204); Manual urinalysis test with examination using microscope, automated (HCPCS 81001). Source: CMS Medicare Physician & Other Practitioners file.