JACOB JOSEF KANTROWITZ MD
NPI 1871055749
Internal Medicine in Boston, MA
About Jacob Josef Kantrowitz Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
JACOB JOSEF KANTROWITZ MD (NPI 1871055749) is an individual internal medicine provider in Boston, Massachusetts, licensed in Massachusetts (285073) and active in the NPI registry since April 2019. He is enrolled in Medicare PECOS, is affiliated with Tufts Medical Center, and maintains a secondary practice location in Warwick.
NPPES Registry Identity
Specialties & Licenses 3
Other Names 1
Secondary Practice Location 1
Accepted Insurance
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
Jacob Josef Kantrowitz 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.
Medicare Billing Reassignments
2Medicare enrollment records show Jacob Kantrowitz reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Quincy, MA 02169
- Reassigned Medicare billing, Massachusetts enrollment
- 334 clinicians in this Medicare group
Watertown, MA 02472
- Reassigned Medicare billing, Massachusetts enrollment
- 1,103 clinicians in this Medicare group
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 3
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.
Hospital Affiliations CMS Care Compare
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Tufts Medical Center
Acute Care Hospitals · Boston, MAPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 02124 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
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.
DORCHESTER, MA 02124
DORCHESTER CENTER, MA 02124
DORCHESTER CENTER, MA 02124
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Jacob Kantrowitz's NPI number?
The NPI number for Jacob Kantrowitz is 1871055749. It was assigned to this individual provider in the NPPES registry on April 1, 2019. The provider is also known as Jacob Josef Kantrowitz-Sirotkin.
Where is Jacob Kantrowitz located?
Jacob Kantrowitz practices at 2100 Dorchester Ave, Boston, MA 02124. The listed phone number is (617) 506-4000.
What is Jacob Kantrowitz's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Jacob Kantrowitz enrolled in Medicare?
Yes. Jacob Kantrowitz is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Jacob Kantrowitz's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Jacob Kantrowitz reassigns Medicare benefits to 2 organizations: Pratt Medical Group, Inc (Quincy, MA) and Steward Medical Group, Inc (Watertown, MA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Jacob Kantrowitz's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Jacob Kantrowitz accept?
Health plans from Anthem Blue Cross and Blue Shield and Taro Health list Jacob Kantrowitz as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Jacob Kantrowitz affiliated with any hospitals?
According to CMS data, Jacob Kantrowitz is affiliated with Tufts Medical Center.
When was this NPI record last updated?
The NPPES record for Jacob Kantrowitz was last updated on August 12, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Jacob Josef Kantrowitz, MD · NPI 1871055749
Internal Medicine physician in Boston, Massachusetts. Individual provider, active in the CMS NPPES registry since April 1, 2019.
## Identity
- **NPI:** 1871055749 (Entity type: Individual)
- **Enumerated:** April 1, 2019
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 285073 (Massachusetts)
- **Sole proprietor:** No
## Practice location
- **Address:** 2100 DORCHESTER AVE, Boston, MA 02124-5666
- **Phone:** (617) 506-4000
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): Pratt Medical Group, Inc (NPI 1447525241, Quincy, MA); Steward Medical Group, Inc (NPI 1629398219, Watertown, MA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Boston University School Of Medicine, class of 2019
## Record status
- **NPPES last updated:** August 12, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1871055749) · Data from the CMS NPPES public registry.