ELLEN SPAR M.D.
NPI 1285686386
Internal Medicine in Boston, MA
About Ellen Spar M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ELLEN SPAR M.D. (NPI 1285686386) is an individual internal medicine provider in Boston, Massachusetts, licensed in Massachusetts (72200) and active in the NPI registry since May 2006. She is enrolled in Medicare PECOS, is affiliated with Mount Auburn Hospital, and is a graduate of Jefferson Medical College Of Thomas Jefferson University (1987).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 5
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
Ellen Spar 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 Reassignment
Medicare enrollment records show Ellen Spar reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Boston, MA 02215
- Reassigned Medicare billing, Massachusetts enrollment
- 1,317 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 44
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 3
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Mount Auburn Hospital
Acute Care Hospitals · Cambridge, MABeth Israel Deaconess Medical Center
Acute Care Hospitals · Boston, MABrigham And Women's Hospital
Acute Care Hospitals · Boston, MAPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 02215 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Referred Medical Equipment & Supplies CMS DME claims 5
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
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.
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 Ellen Spar's NPI number?
The NPI number for Ellen Spar is 1285686386. It was assigned to this individual provider in the NPPES registry on May 17, 2006.
Where is Ellen Spar located?
Ellen Spar practices at 133 Brookline Ave Internal Medicine, Boston, MA 02215. The listed phone number is (617) 421-8843.
What is Ellen Spar's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Ellen Spar enrolled in Medicare?
Yes. Ellen Spar 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 organization bills Medicare for Ellen Spar's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Ellen Spar reassigns Medicare benefits to Atrius Health, Inc. (Boston, MA). The 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 Ellen Spar's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Ellen Spar accept?
Health plans from Anthem Blue Cross and Blue Shield list Ellen Spar 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 Ellen Spar affiliated with any hospitals?
According to CMS data, Ellen Spar is affiliated with Mount Auburn Hospital, Beth Israel Deaconess Medical Center and Brigham And Women's Hospital.
When was this NPI record last updated?
The NPPES record for Ellen Spar was last updated on November 17, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 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.