GREGORY H. SHIMIZU MD
NPI 1154492130
Internal Medicine in Fontana, CA

Q: What is Gregory Shimizu's NPI number?

The NPI number for Gregory Shimizu is 1154492130. It was assigned to this individual provider in the NPPES registry on November 13, 2006.

Q: What is Gregory Shimizu's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Q: When was this NPI record last updated?

The NPPES record for Gregory Shimizu was last updated on September 23, 2008. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 18 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 November 13, 2006PECOS EnrolledAccepts Medicare Assignment

9961 SIERRA AVE, FONTANA, CA 92335(909) 427-3910 Get Directions Write a Review

NPPES record last updated: September 23, 2008. Verified against the NPPES registry weekly; last sync: October 25, 2026.

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About Gregory H. Shimizu Md NPPES

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

GREGORY H. SHIMIZU MD (NPI 1154492130) is an individual internal medicine provider in Fontana, California, licensed in California (G67137) and active in the NPI registry since November 2006. He is enrolled in Medicare PECOS and is a graduate of George Washington University School Of Medicine (1988).

NPPES Registry Identity

NPI1154492130

Entity TypeIndividualMale

Primary Taxonomy207R00000X

Provider Legal NameGREGORY H. SHIMIZUCredential: MD

Location Address9961 SIERRA AVEFontana, CA 92335-6720

Mailing Address9961 Sierra AveFontana, CA 92335-6720 · (909) 427-3910

Phone(909) 427-3910

Sole ProprietorNo

Medical School CMSGeorge Washington University School Of MedicineGraduated 1988

Enumeration DateNovember 13, 2006

Last NPPES UpdateSeptember 23, 2008

✔ NPI 1154492130 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207R00000X

License✔ Licensed in CA · G67137

Definition

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

9961 SIERRA AVE, Fontana, CA 92335

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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

Gregory H. Shimizu 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 ID5395806038

PECOS Enrollment IDI20081212000392

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 Reassignment

Medicare enrollment records show Gregory Shimizu reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Temecula Valley Hospitalist Medical Group, Inc.

45 mi

Internal Medicine

31700 TEMECULA PKWY
Temecula, CA 92592

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

NPI 1265874135 (310) 321-0143

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 6

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.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

357 services171 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232

Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.

232 services104 patients

Advance care planning, first 30 minutes 99497

Advance care planning is a process where you discuss your healthcare preferences with your doctor. This conversation, lasting up to 30 minutes, helps ensure your wishes are respected if you're unable to communicate them in the future. It's about your care, your way.

154 services124 patients

Hospital discharge day management, more than 30 minutes 99239

Hospital discharge day management over 30 minutes involves a detailed process to ensure a smooth transition from hospital to home. It includes final examinations, discussion of your hospital stay, post-discharge instructions, and coordinating follow-up care.

94 services93 patients

Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223

Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.

58 services57 patients

Smoking and tobacco use intensive counseling, more than 10 minutes 99407

This service involves an in-depth discussion about the risks of smoking and tobacco use, spanning over 10 minutes. It provides personalized strategies to quit smoking, including coping techniques for withdrawal symptoms and triggers. The goal is to support your journey towards a healthier lifestyle.

15 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92335 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

$136.04 typical visit price

range $59.60 – $179.42

Typical copayment $34.01 (range $14.90 – $44.85)

Most-billed visit code 99204

Established Patient

$104.64 typical visit price

range $19.37 – $146.42

Typical copayment $26.16 (range $4.84 – $36.60)

Most-billed visit code 99214

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 4

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

Hospital bed, semi-electric (head and foot adjustment), with any type side rails, with mattress E0260

DME-Hospital Beds · category DB000N

1 supplier12 claims12 services$44.78 avg. paid by Medicare

Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390

DME-Oxygen and Supplies · category DC002N

2 suppliers22 claims22 services$66.11 avg. paid by Medicare

Standard wheelchair K0001

DME-Wheelchairs · category DD000N

2 suppliers26 claims26 services$20.76 avg. paid by Medicare

Portable gaseous oxygen system, rental; home compressor used to fill portable oxygen cylinders; includes portable containers, regulator, flowmeter, humidifier, cannula or mask, and tubing K0738

DME-Oxygen and Supplies · category DC000N

1 supplier12 claims12 services$32.54 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 20

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

SHEILA ANN VANALLEN PT

Physical Therapist

9961 SIERRA AVE, BUILDING 3A
FONTANA, CA 92335

San Bernardino County (909) 427-7727

MR. JAMES DAVID KILLEEN III M.D.

Pediatrics

9961 SIERRA AVE, KAISER PERMANENTE FONTANA - PEDIATRICS
FONTANA, CA 92335

San Bernardino County (909) 427-6960

MR. DHIRESH N PATEL RPH

Pharmacist