Quick answers
- Where does John W. Denninger see patients?
- Medicare's clinician data lists 2 practice locations, including Charlestown, MA and Boston, MA. Call before your visit to confirm the address.
- What is John W. Denninger's specialty?
- Medicare lists Psychiatry as the primary specialty.
- Does John W. Denninger accept Medicare assignment?
- Yes. Medicare's clinician data says John W. Denninger 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 John W. Denninger?
- (617) 724-5202, as listed in official Medicare / NPI Registry data.
- What is John W. Denninger's NPI number?
- 1871555888. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Practice locations
Addresses where John W. Denninger is enrolled with Medicare (CMS data updated 2026-10-02).
- 1 Constitution Plz, Suite 140Charlestown, MA 02129 (617) 724‑5202
- 55 Fruit StBoston, MA 02114 (617) 724‑0287
Group practices
Medicare enrollment lists John W. Denninger as a member of this group (CMS data updated 2026-10-02).
- Massachusetts General Physicians Organization Inc3,558 clinicians in the group
Specialties
- Psychiatryprimary
Other psychiatrists in Charlestown
Clinicians with the same Medicare primary specialty in Charlestown, MA — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Michigan Medical School |
| Graduation year | 2000 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1871555888 |
| 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
- 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