Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
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Dr. Norman Shizuaki Nishioka, MD

Individual provider Internal Medicine Physician · NPI 1174513600

Dr. Norman Shizuaki Nishioka, MD practises Gastroenterology in Boston, Massachusetts. Graduated from University of California, Geffen School of Medicine in 1981, 45 years ago. Practices with The General Hospital Corporation, a 1,276-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts.

Years since qualifying
45
Trained at
University of California, Geffen School of Medicine
Licensed in
MA
In the registry since
2005
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

55 Fruit St Gastroenterology Associates Blk 4
Boston, MA 02114-2621
Phone: (617) 726-4422
Fax: (617) 724-6832
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Gastroenterology Physician (primary) Taxonomy 207RG0100X · Licence 51195 (MA)
Internal Medicine Physician Taxonomy 207R00000X · Licence 51195 (MA)

Record details

NPI number1174513600
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 26, 2005
Last updated in NPPESJuly 13, 2026

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyGASTROENTEROLOGY
Also practisesINTERNAL MEDICINE
Medical schoolUNIVERSITY OF CALIFORNIA, GEFFEN SCHOOL OF MEDICINE
Graduated 1981 (45 years in practice)
Group practice The General Hospital Corporation — 1276 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations2 on file with Medicare

Procedures

From CMS Care Compare, which counts the procedures a clinician billed to Original Medicare and Medicare Advantage over a recent 12-month period. CMS reports a fixed list of common procedures, so this is not everything the clinician does. Counts of 10 or fewer are given as a range, because CMS withholds small numbers.

Upper gastrointestinal (GI) endoscopy for acid reflux 258 times · 94th percentile
Colonoscopy 162 times · 90th percentile

The percentile compares how often this clinician performed the procedure with other clinicians who performed it, as CMS calculates it. It measures volume, not outcomes or skill.

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients715
Services billed 1,575 a service is one billed item, such as a visit, a test or a procedure
Average patient age75

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at The General Hospital Corporation

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 1276 clinicians in the practice; 12 are shown here.

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