DR. JANET C LARSON M.D.
NPI 1831159326
Internal Medicine in Boston, MA
About Dr. Janet C Larson M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. JANET C LARSON M.D. (NPI 1831159326) is an individual internal medicine provider in Boston, Massachusetts, licensed in Massachusetts (220603) and active in the NPI registry since March 2006. She is enrolled in Medicare PECOS and is a graduate of Boston University School Of Medicine (1998).
NPPES Registry Identity
Specialties & Licenses 2
Other Names 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
Dr. Janet C Larson M.d. 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 Janet Larson reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Newton, MA 02462
- Reassigned Medicare billing, Massachusetts enrollment
- 992 clinicians in this Medicare group
Philadelphia, PA 19115
- Reassigned Medicare billing, Pennsylvania enrollment
- 1,205 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 02118 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.
BOSTON, MA 02118
BOSTON, MA 02118
BOSTON, MA 02118
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 Janet Larson's NPI number?
The NPI number for Janet Larson is 1831159326. It was assigned to this individual provider in the NPPES registry on March 27, 2006. The provider is also known as Dr. Janet Carlisle Hanousek M.D..
Where is Janet Larson located?
Janet Larson practices at 801 Massachusetts Ave Crosstown 2, Boston, MA 02118. The listed phone number is (617) 414-7399.
What is Janet Larson's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Janet Larson enrolled in Medicare?
Yes. Janet Larson 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 Janet Larson's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Janet Larson reassigns Medicare benefits to 2 organizations: Mass General Brigham Medical Group Suburban Massachusetts Inc (Newton, MA) and Einstein Practice Plan Inc (Philadelphia, PA). 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 Janet Larson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Janet Larson accept?
Health plans from Ambetter Health, Ambetter Health of Delaware and Ambetter from Buckeye Health Plan list Janet Larson 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.
When was this NPI record last updated?
The NPPES record for Janet Larson was last updated on April 3, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.
# Dr. Janet C Larson, M.D. · NPI 1831159326
Internal Medicine physician in Boston, Massachusetts. Individual provider, active in the CMS NPPES registry since March 27, 2006.
## Identity
- **NPI:** 1831159326 (Entity type: Individual)
- **Enumerated:** March 27, 2006
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 220603 (Massachusetts)
- **Sole proprietor:** No
## Practice location
- **Address:** 801 MASSACHUSETTS AVE, CROSSTOWN 2, Boston, MA 02118
- **Phone:** (617) 414-7399 · **Fax:** (617) 414-4676
## 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): Mass General Brigham Medical Group Suburban Massachusetts Inc (NPI 1538191218, Newton, MA); Einstein Practice Plan Inc (NPI 1922050509, Philadelphia, PA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Boston University School Of Medicine, class of 1998
## Record status
- **NPPES last updated:** April 3, 2024
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Source: [NPI Profile](https://npiprofile.com/npi/1831159326) · Data from the CMS NPPES public registry.