Quick answers
- Does Sadie Elisseou accept Medicare assignment?
- Yes. Medicare's clinician data says Sadie Elisseou accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- What is Sadie Elisseou's NPI number?
- 1699090902. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Sadie Elisseou works
Medicare's Facility Affiliation Data lists Sadie Elisseou at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.
- Brigham and Women's HospitalBoston, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220110
- Massachusetts General HospitalBoston, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220071
- Newton-Wellesley HospitalNewton, MA · Acute Care Hospital · Medicare rating: 5 of 5 stars · Emergency services: listed by Medicare · CCN 220101
Practice locations
Addresses where Sadie Elisseou is enrolled with Medicare (CMS data updated October 2, 2026).
- 173 Worcester StWellesley, MA 02481 (671) 831‑7000
- 2014 Washington StNewton, MA 02462 (617) 243‑6000
Group practices
Medicare enrollment lists Sadie Elisseou as a member of this group (CMS data updated October 2, 2026).
- Mass General Brigham Medical Group Suburban Massachusetts Inc602 clinicians in the group
Specialties
- Internal Medicineprimary
Other internal medicine doctors in Wellesley
Clinicians with the same Medicare primary specialty in Wellesley, MA — not a recommendation.
Other clinicians in Mass General Brigham Medical Group Suburban Massachusetts Inc
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Warren Alpert Medical School Of Brown University |
| Graduation year | 2010 (16 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1699090902 |
| Corrections | Report 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
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
- Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
- National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians