Doctor profile · Federal record
Dr. Mark Northfield, MD
Orthopaedic Surgery Physician (CMS: Orthopedic Surgery) · Petaluma, CA
- NPI 1861406316
- Accepts Medicare
- 35 yrs in practice
- Male
- Solo practice
- No sanctions
Practice & contact
- Primary practice
-
1496 Professional Drive, Suite 601
Petaluma, CA 94954
(707) 778-1131
fax (707) 778-3818
Credentials & registration
- NPI registered
- July 2006 — 20 yrs on file
- Profile last updated
- November 9, 2021
- Year of graduation
- 1991 — 35 yrs since
- Specialty taxonomy
- 207X00000X — NUCC code
- State license (1)
- California #G77114
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1861406316. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
2,009
Distinct HCPCS
10
Medicare allowed
$94,423
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
J3301 |
Injection, triamcinolone acetonide, not otherwise specified, 10 mg | 966 | 98 | $1 | |
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 309 | 197 | $98 | |
20610 |
Aspiration and/or injection of fluid from large joint | 191 | 111 | $79 | |
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 82 | 73 | $137 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 75 | 75 | $179 | |
J7321 |
Hyaluronan or derivative, hyalgan, supartz or visco-3, for intra-articular injection, per dose | 63 | 16 | $73 | |
99203 |
New patient office or other outpatient visit, 30-44 minutes | 58 | 58 | $122 | |
99212 |
Established patient office or other outpatient visit, 10-19 minutes | 52 | 23 | $62 | |
73562 |
X-ray of knee, 3 views | 50 | 47 | $48 | |
73030 |
X-ray of shoulder, minimum of 2 views | 36 | 31 | $40 |
In context: peer comparison
Among 1 peers in Petaluma Orthopaedic Surgery Physician, average services per provider: 125. This provider delivers 16× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
237
Patients
50
Total drug cost
$2,039
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) | Brand | 105 | 24 | $878 |
| Oxycodone-Acetaminophen (Oxycodone Hcl/Acetaminophen) | Brand | 41 | 0 | $460 |
| Celecoxib | Generic | 22 | 0 | $362 |
| Oxycodone Hcl | Generic | 19 | 12 | $141 |
| Tramadol Hcl | Generic | 15 | 14 | $42 |
| Naproxen | Generic | 13 | 0 | $73 |
| Azithromycin | Generic | 11 | 0 | $51 |
| Gabapentin | Generic | 11 | 0 | $31 |
Frequently asked questions
What is Dr. Mark Northfield's medical specialty?
Dr. Mark Northfield practices Orthopaedic Surgery Physician in Petaluma, CA.
Where does Dr. Mark Northfield practice?
Dr. Mark Northfield practices at 1496 Professional Drive, Petaluma, CA 94954. Office phone: 7077781131.
What is Dr. Mark Northfield's NPI?
Dr. Mark Northfield's National Provider Identifier (NPI) is 1861406316, issued by NPPES.
Does Dr. Mark Northfield accept Medicare assignment?
Yes. Dr. Mark Northfield accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mark Northfield commonly perform?
Top Medicare-reported procedures in 2023: Injection, triamcinolone acetonide, not otherwise specified, 10 mg (HCPCS J3301); Established patient office or other outpatient visit (HCPCS 99213); Aspiration and/or injection of fluid from large joint (HCPCS 20610). Source: CMS Medicare Physician & Other Practitioners file.