Quick answers
- Which hospitals does Benjamin Mazer work at?
- Medicare's official clinician data lists Benjamin Mazer at 1 hospital: Johns Hopkins Bayview Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Benjamin Mazer see patients?
- Medicare's clinician data lists 4 practice locations, including Baltimore, MD, Columbia, MD and Middle River, MD. Call before your visit to confirm the address.
- What is Benjamin Mazer's specialty?
- Medicare lists Pathology as the primary specialty.
- Does Benjamin Mazer accept Medicare assignment?
- Medicare's clinician data says Benjamin Mazer may accept Medicare assignment (as of 2026-10-02). Ask the office whether they accept it for your visit.
- What is the phone number for Benjamin Mazer?
- (410) 740-7890, as listed in official Medicare / NPI Registry data.
- What is Benjamin Mazer's NPI number?
- 1689022352. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Benjamin Mazer works
Medicare's Facility Affiliation Data lists Benjamin Mazer at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Johns Hopkins Bayview Medical CenterBaltimore, MD · Acute Care Hospital · CCN 210029
Practice locations
Addresses where Benjamin Mazer is enrolled with Medicare (CMS data updated 2026-10-02).
- 4940 Eastern AveBaltimore, MD 21224
- 5755 Cedar LnColumbia, MD 21044 (410) 740‑7890
- 5759 Cedar LnColumbia, MD 21044
- 6201 Greenleigh AveMiddle River, MD 21220
Group practices
Medicare enrollment lists Benjamin Mazer as a member of these groups (CMS data updated 2026-10-02).
- Johns Hopkins University2,909 clinicians in the group
- Johns Hopkins University713 clinicians in the group
Specialties
- Pathologyprimary
Other pathologists in Baltimore
Clinicians with the same Medicare primary specialty in Baltimore, MD — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Rochester School Of Medicine And Dentistry |
| Graduation year | 2016 |
| Gender (as listed) | Male |
| Medicare assignment | May accept for some services |
| NPI (National Provider Identifier) | 1689022352 |
| 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