Quick answers
- Where does Mark K. Detweiler see patients?
- Medicare's clinician data lists 1 practice location in Londonderry, NH. Call before your visit to confirm the address.
- What is Mark K. Detweiler's specialty?
- Medicare lists Gastroenterology as the primary specialty.
- Does Mark K. Detweiler accept Medicare assignment?
- Yes. Medicare's clinician data says Mark K. Detweiler 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 K. Detweiler?
- (603) 818-4712, as listed in official Medicare / NPI Registry data.
- What is Mark K. Detweiler's NPI number?
- 1548344583. 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 Mark K. Detweiler is enrolled with Medicare (CMS data updated 2026-10-02).
- 1 B Commons Dr, Unit 9aLondonderry, NH 03053 (603) 818‑4712
Specialties
- Gastroenterologyprimary
Other gastroenterologists in New Hampshire
Clinicians with the same Medicare primary specialty in New Hampshire — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Pennsylvania State University College Of Medicine |
| Graduation year | 1979 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1548344583 |
| 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