DR. MARK R NORTHFIELD MD
NPI 1861406316
Orthopaedic Surgery in Petaluma, CA

Q: What is Mark Northfield's NPI number?

The NPI number for Mark Northfield is 1861406316. It was assigned to this individual provider in the NPPES registry on July 28, 2006.

Q: What is Mark Northfield's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery with taxonomy code 207X00000X.

Q: When was this NPI record last updated?

The NPPES record for Mark Northfield was last updated on November 9, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since July 28, 2006PECOS EnrolledAccepts Medicare Assignment

1496 PROFESSIONAL DRIVE, SUITE 601, PETALUMA, CA 94954(707) 778-1131(707) 778-3818 Get Directions Write a Review

NPPES record last updated: November 9, 2021. Verified against the NPPES registry weekly; last sync: August 09, 2026.

Record update history: Nov 9, 2021, Feb 4, 2021 (2 updates tracked since 2021).

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About Dr. Mark R Northfield Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. MARK R NORTHFIELD MD (NPI 1861406316) is an individual orthopaedic surgery provider in Petaluma, California, licensed in California (G77114) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS and is a graduate of Warren Alpert Medical School Of Brown University (1991).

NPPES Registry Identity

NPI1861406316

Entity TypeIndividualMale

Primary Taxonomy207X00000X

Provider Legal NameDR. MARK R NORTHFIELDCredential: MD

Location Address1496 PROFESSIONAL DRIVE, SUITE 601Petaluma, CA 94954

Mailing Address1496 Professional Drive, Suite 601Petaluma, CA 94954 · (707) 778-1131 · Fax (707) 778-3818

Phone(707) 778-1131

Fax(707) 778-3818

Sole ProprietorYes

Medical School CMSWarren Alpert Medical School Of Brown UniversityGraduated 1991

Enumeration DateJuly 28, 2006

Last NPPES UpdateNovember 9, 20212 updates tracked since enumeration

NPPES CertifiedNovember 9, 2021

✔ NPI 1861406316 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOrthopaedic SurgeryAllopathic & Osteopathic Physicians

Taxonomy Code207X00000X

License✔ Licensed in CA · G77114

Definition

An orthopaedic surgeon is trained in the preservation, investigation and restoration of the form and function of the extremities, spine and associated structures by medical, surgical and physical means. An orthopaedic surgeon is involved with the care of patients whose musculoskeletal problems include congenital deformities, trauma, infections, tumors, metabolic disturbances of the musculoskeletal system, deformities, injuries and degenerative diseases of the spine, hands, feet, knee, hip, shoulder and elbow in children and adults. An orthopaedic surgeon is also concerned with primary and secondary muscular problems and the effects of central or peripheral nervous system lesions of the musculoskeletal system.

1496 PROFESSIONAL DRIVE, Petaluma, CA 94954

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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Mark R Northfield Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID3779608997

PECOS Enrollment IDI20100913000041

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 12

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

256 services169 patients

Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3301

Triamcinolone acetonide is a medication used to reduce inflammation in the body. It's given as a 10 mg injection for conditions like allergies, arthritis, or skin problems. The injection helps to decrease swelling, redness, and itching.

241 services51 patients

Aspiration and/or injection of fluid from large joint 20610

This procedure involves using a needle to remove (aspiration) or introduce (injection) fluid into a large joint like the knee or hip. It can help diagnose conditions, relieve discomfort, or deliver medication directly to the joint.

180 services116 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

145 services110 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

115 services115 patients

X-ray of knee, 3 views 73562

An X-ray of the knee, 3 views, is a non-invasive imaging test. It uses a small amount of radiation to produce images of the knee from three different angles. This helps medical professionals to diagnose and monitor conditions like arthritis, fractures, or infections. The process is quick and painless.

44 services44 patients

New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203

This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.

34 services34 patients

X-ray of shoulder, minimum of 2 views 73030

An X-ray of the shoulder, with a minimum of 2 views, is a non-invasive imaging test. It uses a small amount of radiation to produce images of your shoulder bones. This helps in diagnosing conditions like fractures, arthritis, or other abnormalities. The procedure is quick and painless.

28 services23 patients

X-ray of hip, 1 view 73501

An X-ray of the hip, 1 view, is a quick, painless test where a small amount of radiation is used to produce images of the hip joint. This helps in diagnosing conditions like arthritis or fractures. You'll be positioned so that the X-ray machine can capture the best image of your hip.

26 services23 patients

Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

23 services16 patients

X-ray of lower and sacral spine, 2-3 views 72100

An X-ray of the lower and sacral spine involves capturing images of your lower back area, including the tailbone. This procedure helps in identifying problems like fractures, infections, or deformities. 2-3 different angle views provide a comprehensive picture.

14 services14 patients

Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222

Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.

12 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94954 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$96.16 typical visit price

range $63.04 – $187.01

Typical copayment $24.04 (range $15.76 – $46.75)

Most-billed visit code 99203

Established Patient

$77.94 typical visit price

range $21.02 – $153.40

Typical copayment $19.48 (range $5.25 – $38.35)

Most-billed visit code 99213

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Dynamic adjustable knee extension / flexion device, includes soft interface material E1810

DME-Other DME · category DE000N

1 supplier12 claims12 services$97.05 avg. paid by Medicare

Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

DR. JAMES J GLYNN MD,

Orthopaedic Surgery

1496 PROFESSIONAL DRIVE, SUITE 601
PETALUMA, CA 94954

Sonoma County (707) 778-1131

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Mark Northfield's NPI number?

The NPI number for Mark Northfield is 1861406316. It was assigned to this individual provider in the NPPES registry on July 28, 2006.

Where is Mark Northfield located?

Mark Northfield practices at 1496 Professional Drive Suite 601, Petaluma, CA 94954. The listed phone number is (707) 778-1131.

What is Mark Northfield's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery with taxonomy code 207X00000X.

Is Mark Northfield enrolled in Medicare?

Yes. Mark Northfield is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

When was this NPI record last updated?

The NPPES record for Mark Northfield was last updated on November 9, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.