Quick answers
- Which hospitals does Mark E. Alexander work at?
- Medicare's official clinician data lists Mark E. Alexander at 1 hospital: Boston Children's Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark E. Alexander see patients?
- Medicare's clinician data lists 1 practice location in Boston, MA. Call before your visit to confirm the address.
- What is Mark E. Alexander's specialty?
- Medicare lists Pediatric Medicine as the primary specialty, and also Cardiovascular Disease (Cardiology).
- Does Mark E. Alexander accept Medicare assignment?
- Yes. Medicare's clinician data says Mark E. Alexander accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Mark E. Alexander?
- (617) 355-6000, as listed in official Medicare / NPI Registry data.
- What is Mark E. Alexander's NPI number?
- 1013907666. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Mark E. Alexander works
Medicare's Facility Affiliation Data lists Mark E. Alexander 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 Mark E. Alexander is enrolled with Medicare (CMS data updated 2026-10-02).
- 300 Longwood AveBoston, MA 02115 (617) 355‑6000
Group practices
Medicare enrollment lists Mark E. Alexander as a member of this group (CMS data updated 2026-10-02).
- Boston Childrens Heart Foundation Inc100 clinicians in the group
Specialties
Other pediatricians in Boston
Clinicians with the same Medicare primary specialty in Boston, MA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Northwestern University Feinberg Medical School |
| Graduation year | 1985 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1013907666 |
| 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