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Rheumatology

Guy Katz, MD

Works at hospitals in Boston, MA · Salem, MA · Northampton, MA … · Massachusetts, New Hampshire

Summary

Guy Katz, MD (Rheumatology) is listed by Medicare at 5 hospitals in Boston, MA, Salem, MA and Northampton, MA and other places. NPI 1285168187. Medicare data says the clinician accepts Medicare assignment. Source: CMS Facility Affiliation Data, updated 2026-10-02.

From official Medicare data

This page shows what Medicare's official clinician data says about Guy Katz, joined by NPI number (data updated 2026-10-02). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

At a glance

RheumatologyPrimary specialty
YesAccepts Medicare assignment
YesOffers telehealth
9Years since medical school (graduated 2017)
Icahn School Of Medicine At Mount SinaiMedical school
MaleGender (as listed)
Massachusetts General Physicians Organization IncGroup practice (+1 more)

Quick answers

Which hospitals does Guy Katz work at?
Medicare's official clinician data lists Guy Katz at 5 hospitals: Brigham and Women's Hospital, Massachusetts General Hospital, North Shore Medical Center -, The Cooley Dickinson Hospital Inc and Wentworth-Douglass Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Guy Katz see patients?
Medicare's clinician data lists 1 practice location in Boston, MA. Call before your visit to confirm the address.
What is Guy Katz's specialty?
Medicare lists Rheumatology as the primary specialty, and also Internal Medicine.
Does Guy Katz accept Medicare assignment?
Yes. Medicare's clinician data says Guy Katz accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
Does Guy Katz offer telehealth?
Medicare's clinician data says Guy Katz offers telehealth services. Ask the office which visits can be done by video or phone.
What is the phone number for Guy Katz?
(617) 726-2000, as listed in official Medicare / NPI Registry data.
What is Guy Katz's NPI number?
1285168187. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Guy Katz works

Medicare's Facility Affiliation Data lists Guy Katz at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.

Practice locations

Addresses where Guy Katz is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Guy Katz as a member of these groups (CMS data updated 2026-10-02).

  • Massachusetts General Physicians Organization Inc3,558 clinicians in the group
  • The General Hospital Corporation1,267 clinicians in the group

Specialties

Find other Rheumatology doctors in Massachusetts →

Other rheumatologists in Boston

Clinicians with the same Medicare primary specialty in Boston, MA — not a recommendation.

All rheumatologists in Boston →

Clinician information

CredentialMD
Medical schoolIcahn School Of Medicine At Mount Sinai
Graduation year2017
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1285168187
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
  2. National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians