Medical emergency?Emergency? Call 911. Nearest emergency roomsNearest ERs

Internal Medicine

Kelsey D. Sack, MD

Works at hospitals in Boston, MA · Massachusetts

Summary

Kelsey D. Sack, MD (Internal Medicine) is listed by Medicare at 1 hospital in Boston, MA. NPI 1710415344. 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 Kelsey D. Sack, 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

Internal MedicinePrimary specialty
YesAccepts Medicare assignment
9Years since medical school (graduated 2017)
Boston University School Of MedicineMedical school
FemaleGender (as listed)
Harvard Medical Faculty Phys at Beth Israel Deaconess Med Ctr IncGroup practice

Quick answers

Which hospitals does Kelsey D. Sack work at?
Medicare's official clinician data lists Kelsey D. Sack at 1 hospital: Beth Israel Deaconess Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
Where does Kelsey D. Sack see patients?
Medicare's clinician data lists 2 practice locations, including Boston, MA. Call before your visit to confirm the address.
What is Kelsey D. Sack's specialty?
Medicare lists Internal Medicine as the primary specialty.
Does Kelsey D. Sack accept Medicare assignment?
Yes. Medicare's clinician data says Kelsey D. Sack 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.
What is the phone number for Kelsey D. Sack?
(781) 983-9088, as listed in official Medicare / NPI Registry data.
What is Kelsey D. Sack's NPI number?
1710415344. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Hospitals where Kelsey D. Sack works

Medicare's Facility Affiliation Data lists Kelsey D. Sack 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 Kelsey D. Sack is enrolled with Medicare (CMS data updated 2026-10-02).

Group practices

Medicare enrollment lists Kelsey D. Sack as a member of this group (CMS data updated 2026-10-02).

  • Harvard Medical Faculty Phys at Beth Israel Deaconess Med Ctr Inc1,740 clinicians in the group

Specialties

Find other Internal Medicine doctors in Massachusetts →

Other internal medicine doctors in Boston

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

All internal medicine doctors in Boston →

Clinician information

CredentialMD
Medical schoolBoston University School Of Medicine
Graduation year2017
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1710415344
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