DR. WILLIAM N GONSER M.D.
NPI 1952348617
Radiology - Diagnostic Radiology in Fairfield, CA

Q: What is William Gonser's NPI number?

The NPI number for William Gonser is 1952348617. It was assigned to this individual provider in the NPPES registry on June 1, 2006.

Q: What is William Gonser's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Diagnostic Radiology, with taxonomy code 2085R0202X.

Q: When was this NPI record last updated?

The NPPES record for William Gonser was last updated on April 16, 2012. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 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 June 01, 2006PECOS EnrolledAccepts Medicare Assignment

98.42/100

CMS Quality Rating

1200 B GALE WILSON BLVD, FAIRFIELD, CA 94533(707) 464-6510(707) 256-3508 Get Directions Write a Review

NPPES record last updated: April 16, 2012. Verified against the NPPES registry weekly; last sync: October 18, 2026.

On this page

About Dr. William N Gonser M.d. NPPES

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

DR. WILLIAM N GONSER M.D. (NPI 1952348617) is an individual diagnostic radiology provider in Fairfield, California, licensed in California (G73301) and active in the NPI registry since June 2006. He is enrolled in Medicare PECOS and is a graduate of Saint Louis University School Of Medicine (1988).

NPPES Registry Identity

NPI1952348617

Entity TypeIndividualMale

Primary Taxonomy2085R0202X

Provider Legal NameDR. WILLIAM N GONSERCredential: M.D.

Location Address1200 B GALE WILSON BLVDFairfield, CA 94533-3552

Mailing AddressPo Box 3222Napa, CA 94558-0293 · (707) 261-7804 · Fax (707) 256-3508

Phone(707) 464-6510

Fax(707) 256-3508

Sole ProprietorNo

Medical School CMSSaint Louis University School Of MedicineGraduated 1988

Enumeration DateJune 1, 2006

Last NPPES UpdateApril 16, 2012

✔ NPI 1952348617 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyRadiology · Diagnostic RadiologyAllopathic & Osteopathic Physicians

Taxonomy Code2085R0202X

License✔ Licensed in CA · G73301

Definition

A radiologist who utilizes x-ray, radionuclides, ultrasound and electromagnetic radiation to diagnose and treat disease.

1200 B GALE WILSON BLVD, Fairfield, CA 94533

Open in Google Maps ↗

Other Identifiers 4

Medicare UPINF35560CA

Medicare ID-Type Unspecified00G733011CA · Individual Provider Id

Medicare ID-Type Unspecified00G733010CA · Individual Provider Id

Medicaid00G733010CA

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. William N Gonser M.d. 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 ID3971597378

PECOS Enrollment IDI20040408001602

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.

Medicare Billing Reassignments

Medicare enrollment records show William Gonser reassigns Medicare billing to 8 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Adventist Health Physicians Network

0.2 mi

Multi-Specialty

1620 PENNSYLVANIA AVE, SUITE B
Fairfield, CA 94533

Reassigned Medicare billing, California enrollment
678 clinicians in this Medicare group

NPI 1568801918 (707) 557-3200

Adventist Health Clearlake Hospital Inc.

56 mi

Critical Access

15630 18TH AVE
Clearlake, CA 95422

Reassigned Medicare billing, California enrollment
37 clinicians in this Medicare group

NPI 1124018031 (707) 994-6486

Ukiah Adventist Hospital

88 mi

General Acute Care Hospital

275 HOSPITAL DR
Ukiah, CA 95482

Reassigned Medicare billing, California enrollment
221 clinicians in this Medicare group

NPI 1235120676 (707) 463-7360

Willits Hospital Inc.

112 mi

Critical Access

1 MARCELA DRIVE
Willits, CA 95490

Reassigned Medicare billing, California enrollment
134 clinicians in this Medicare group

NPI 1356339543 (707) 459-6801

Reedley Community Hospital

183 mi

General Acute Care Hospital

372 W. CYPRESS AVE
Reedley, CA 93654

Reassigned Medicare billing, California enrollment
315 clinicians in this Medicare group

NPI 1336167550 (559) 638-8155

Hanford Community Hospital

187 mi

General Acute Care Hospital

115 MALL DR
Hanford, CA 93230

Reassigned Medicare billing, California enrollment
139 clinicians in this Medicare group

NPI 1538141627 (559) 582-9000

Adventist Health Tulare

205 mi

General Acute Care Hospital

869 N CHERRY ST
Tulare, CA 93274

Reassigned Medicare billing, California enrollment
119 clinicians in this Medicare group

NPI 1801366711 (559) 688-0821

Radiology Medical Group Of Wmmc

361 mi

Diagnostic Radiology

1720 E CESAR E CHAVEZ AVE
Los Angeles, CA 90033

Reassigned Medicare billing, California enrollment
53 clinicians in this Medicare group

NPI 1831123868 (626) 795-1610

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 22

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.

X-ray of chest, 1 view 71045

A chest X-ray, 1 view, is a quick, painless test that produces images of the structures within your chest, such as your heart, lungs, and blood vessels. It helps in diagnosing conditions like pneumonia, heart problems, or lung cancer. You'll stand in front of a machine that emits X-rays, which pass through your body to create the image.

269 services222 patients

Imaging guidance for procedure, 60 minutes or less 76000

Imaging guidance is a procedure where real-time images are used to direct medical tools during a treatment. This technique helps to improve accuracy and safety. The procedure typically lasts 60 minutes or less.

66 services64 patients

Ct scan head or brain without contrast 70450

A CT scan of the head or brain without contrast is a non-invasive imaging procedure. It uses X-rays to create detailed pictures of your brain, skull, and other structures inside your head. It helps to detect conditions like strokes, tumors, or injuries. No dye (contrast) is used in this test.

65 services58 patients

X-ray of chest, 2 views 71046

A chest X-ray, 2 views, is a quick, painless test that creates pictures of the structures inside your chest, such as your heart, lungs, and blood vessels. Two different angles are used to get a comprehensive view. This helps in diagnosing conditions like pneumonia, heart problems, or lung cancer.

47 services45 patients

X-ray of pelvis, 1-2 views 72170

An X-ray of the pelvis, 1-2 views, is a quick and painless imaging test. It uses a small amount of radiation to produce images of the lower part of your torso. These images help to detect any abnormalities or injuries in your hip bones and surrounding structures.

43 services42 patients

X-ray of knee, 1-2 views 73560

An X-ray of the knee with 1-2 views is a quick, painless test that produces images of the knee bones. It helps identify fractures, infections, or changes in the knee joint. During the procedure, you'll be asked to stay still while the X-ray machine captures the images.

43 services42 patients

Mri scan of brain without contrast 70551

An MRI scan of the brain without contrast is a non-invasive imaging test. It uses a magnetic field and radio waves to create detailed images of your brain. It helps in detecting abnormalities like tumors, stroke, inflammation, or infection.

34 services34 patients

Ct scan of abdomen and pelvis with contrast 74177

A CT scan of the abdomen and pelvis with contrast is an imaging procedure. A special dye, called contrast, is used to make certain areas more visible. This can help identify issues such as infections, tumors, or other abnormalities. The procedure is painless and usually takes about 30 minutes.

31 services30 patients

X-ray of abdomen, 1 view 74018

An X-ray of the abdomen, 1 view, is a quick and painless imaging test. It uses a small amount of radiation to produce images of the structures in your abdomen, such as the stomach, liver, and intestines. This can help identify issues like blockages, infections, or injuries.

30 services26 patients

X-ray of hip, 2-3 views 73502

An X-ray of the hip with 2-3 views is a non-invasive imaging test. It uses a small amount of radiation to produce pictures of the hip joint. These images help in diagnosing conditions like fractures, arthritis, or other abnormalities. The process is quick and painless.

28 services27 patients

Complete ultrasound scan behind abdominal cavity 76770

A complete ultrasound scan behind the abdominal cavity is a non-invasive imaging procedure. It uses sound waves to create pictures of the structures and organs located at the back of your abdomen. It helps in diagnosing health conditions and monitoring ongoing treatments.

23 services23 patients

3d radiographic procedure 76376

A 3D radiographic procedure is a non-invasive imaging test that helps doctors visualize the internal structures of your body in three dimensions. This advanced technology provides detailed images, aiding in accurate diagnosis and treatment planning. It involves exposure to minimal radiation.

21 services20 patients

Ultrasound study of one arm or leg veins with compression and maneuvers 93971

This is a non-invasive procedure using sound waves to visualize veins in an arm or leg. It involves applying gentle pressure and performing certain movements. It helps identify any abnormal blood flow or clots, ensuring vascular health.

21 services20 patients

Ct scan of blood vessels of chest with contrast 71275

A CT scan of the chest with contrast is a non-invasive imaging test. It uses X-rays and a special dye to get detailed images of your blood vessels in the chest. This helps in diagnosing conditions related to heart and lungs.

18 services18 patients

Ct scan of abdomen and pelvis without contrast 74176

A CT scan of the abdomen and pelvis is a non-invasive medical test. It uses special X-ray equipment to create detailed images of your abdominal and pelvic areas. This helps doctors examine organs, tissues, and vessels. No contrast dye is used in this procedure.

18 services18 patients

Ct scan of chest with contrast 71260

A CT scan of the chest with contrast is an imaging procedure. A special dye (contrast) is used to highlight specific areas in your body, providing clearer pictures of your chest. This helps in diagnosing conditions related to your lungs, heart, and other chest structures.

14 services14 patients

X-ray of shoulder, 1 view 73020

An X-ray of the shoulder, 1 view, is a quick, painless test that produces images of the bones and tissues within your shoulder. It helps diagnose conditions such as fractures, infections, or arthritis. You'll be positioned to capture the best view, then a small dose of radiation creates the image.

13 services13 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.

13 services13 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.

12 services12 patients

Ct scan of blood vessels of head with contrast 70496

A CT scan of the head's blood vessels with contrast is a diagnostic procedure. A special dye (contrast) is injected into your body to make the blood vessels visible on the scan. This helps identify issues like blockages or abnormalities in your head's blood vessels.

11 services11 patients

Ct scan of blood vessels of neck with contrast 70498

A CT scan of the neck's blood vessels with contrast is a diagnostic procedure. It uses X-rays and a special dye to create detailed images of your neck's blood vessels. This helps doctors detect issues such as blockages or abnormalities.

11 services11 patients

Ct scan of chest without contrast 71250

A CT scan of the chest without contrast is a non-invasive imaging procedure. It uses special X-ray equipment to produce detailed images of your chest area, including your lungs and heart. It can help diagnose conditions such as lung diseases or heart disorders. It doesn't involve any dyes or contrast agents.

11 services11 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94533 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

$98.85 typical visit price

range $65.02 – $191.95

Typical copayment $24.71 (range $16.25 – $47.98)

Most-billed visit code 99203

Established Patient

$80.24 typical visit price

range $21.86 – $157.69

Typical copayment $20.06 (range $5.46 – $39.42)

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.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

98.42/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored as part of a group practice

Quality

84.7

Promoting Interoperability

Improvement Activities

Cost

96.71

Reported Quality Measures

Radiation Consideration for Adult CT: Utilization of Dose Lowering Techniques

Percentage of final reports for patients aged 18 years and older undergoing CT with documentation that one or more of the following dose reduction techniques were used: - Automated exposure control - Adjustment of the mA and/or kV according to patient size -…

100%370 patients

Radiology: Reminder System for Screening Mammograms

Percentage of patients undergoing a screening mammogram whose information is entered into a reminder system with a target due date for the next mammogram

99%134 patients

Radiology: Stenosis Measurement in Carotid Imaging Reports

Percentage of final reports for carotid imaging studies (neck magnetic resonance angiography [MRA], neck computed tomography angiography [CTA], neck duplex ultrasound, carotid angiogram) performed that include direct or indirect reference to measurements of…

26%43 patients

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Other Providers at the Same Location NPPES 20

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

DR. JOSEPH J DOMINGUEZ M.D.

Anesthesiology

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (916) 481-6800

DR. JEFFREY J SAADI M.D.

Anesthesiology

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (916) 481-6800

SETH ABRAHAM KAUFMAN M.D.

Emergency Medicine

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (707) 429-7830

JULIE ANN HERSK M.D.

Emergency Medicine

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (707) 429-3600

ANGELINE SABRINA ZARGHAMI RN

Registered Nurse

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (707) 646-4166

JUDY GEIB GONZALES RN

Registered Nurse

1200 B GALE WILSON BLVD, LINDA PRYOR, CORPORATE COMPLIANCE
FAIRFIELD, CA 94533

Solano County (707) 864-5383

LAURENCE CECILIO NP

Nurse Practitioner (Acute Care)

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (707) 646-5000

NORTHBAY HEALTH FOUNDATION

Dietitian, Registered

1200 B GALE WILSON BLVD
FAIRFIELD, CA 94533

Solano County (707) 646-5000

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 William Gonser's NPI number?

The NPI number for William Gonser is 1952348617. It was assigned to this individual provider in the NPPES registry on June 1, 2006.

Where is William Gonser located?

William Gonser practices at 1200 B Gale Wilson Blvd, Fairfield, CA 94533. The listed phone number is (707) 464-6510.

What is William Gonser's specialty?

The primary specialty registered for this NPI is Radiology, specializing in Diagnostic Radiology, with taxonomy code 2085R0202X.

Is William Gonser enrolled in Medicare?

Yes. William Gonser 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.

Which organizations bill Medicare for William Gonser's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Gonser reassigns Medicare benefits to 8 organizations: Adventist Health Physicians Network (Fairfield, CA), Adventist Health Clearlake Hospital Inc. (Clearlake, CA), Ukiah Adventist Hospital (Ukiah, CA), Willits Hospital Inc. (Willits, CA), Reedley Community Hospital (Reedley, CA) and 3 more organizations, listed in the Medicare section above. Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for William Gonser's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for William Gonser was last updated on April 16, 2012. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 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.