Quick answers
- Which hospitals does Marissa A. Sylvia work at?
- Medicare's official clinician data lists Marissa A. Sylvia at 1 hospital: Boston Children's Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Marissa A. Sylvia see patients?
- Medicare's clinician data lists 1 practice location in Boston, MA. Call before your visit to confirm the address.
- What is Marissa A. Sylvia's specialty?
- Medicare lists Nurse Practitioner as the primary specialty.
- Does Marissa A. Sylvia accept Medicare assignment?
- Medicare's clinician data says Marissa A. Sylvia may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is Marissa A. Sylvia's NPI number?
- 1609746940. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Marissa A. Sylvia works
Medicare's Facility Affiliation Data lists Marissa A. Sylvia at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Boston Children's HospitalBoston, MA · Children's Hospital · CCN 223302
Practice locations
Addresses where Marissa A. Sylvia is enrolled with Medicare (CMS data updated 2026-10-02).
- 300 Longwood AveBoston, MA 02115
Group practices
Medicare enrollment lists Marissa A. Sylvia as a member of this group (CMS data updated 2026-10-02).
- Children's Hospital Radiology Foundation, Inc.58 clinicians in the group
Specialties
- Nurse Practitionerprimary
Other nurse practitioners in Boston
Clinicians with the same Medicare primary specialty in Boston, MA — not a recommendation.
Clinician information
| Credential | NP |
|---|---|
| Graduation year | 2024 |
| Gender (as listed) | Female |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1609746940 |
| 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 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- 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