Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

John A Gelzhiser, MD

Individual provider Internal Medicine Physician · NPI 1013100759

John A Gelzhiser, MD practises Internal Medicine in Warwick, Rhode Island. Qualified in 2004, 22 years ago. Practices with Affinity Physicians LLC, a 734-clinician group and accepts Medicare assignment. Licensed in Rhode Island.

Years since qualifying
22
Licensed in
RI
In the registry since
2007
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

455 Toll Gate Rd
Warwick, RI 02886-2759 Not confirmed with CMS for 19 years — call before visiting
Phone: (401) 737-7000
Fax: (401) 736-4265
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence PENDING (RI)

Record details

NPI number1013100759
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedAugust 27, 2007
Last updated in NPPESAugust 27, 2007

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolOTHER
Graduated 2004 (22 years in practice)
Group practice Affinity Physicians Llc. — 734 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

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 patients364
Services billed 805 a service is one billed item, such as a visit, a test or a procedure
Average patient age83

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. Those with a page here are linked.

Colleagues at Affinity Physicians LLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 734 clinicians in the practice; 12 are shown here.

Other providers in Warwick