Quick answers
- Which hospitals does Mark C. Nitzberg work at?
- Medicare's official clinician data lists Mark C. Nitzberg at 4 hospitals: Holy Family Hospital, Merrimack Health Lawrence Hospital, Northeast Hospital Corporation and Winchester Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark C. Nitzberg see patients?
- Medicare's clinician data lists 4 practice locations, including Salem, NH and Methuen, MA. Call before your visit to confirm the address.
- What is Mark C. Nitzberg's specialty?
- Medicare lists Gastroenterology as the primary specialty, and also Internal Medicine.
- Does Mark C. Nitzberg accept Medicare assignment?
- Yes. Medicare's clinician data says Mark C. Nitzberg 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.
- Does Mark C. Nitzberg offer telehealth?
- Medicare's clinician data says Mark C. Nitzberg offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Mark C. Nitzberg?
- (603) 401-6466, as listed in official Medicare / NPI Registry data.
- What is Mark C. Nitzberg's NPI number?
- 1881652758. 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 C. Nitzberg works
Medicare's Facility Affiliation Data lists Mark C. Nitzberg at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Holy Family HospitalMethuen, MA · Acute Care Hospital · CCN 220080
- Merrimack Health Lawrence HospitalLawrence, MA · Acute Care Hospital · CCN 220010
- Northeast Hospital CorporationBeverly, MA · Acute Care Hospital · CCN 220033
- Winchester HospitalWinchester, MA · Acute Care Hospital · CCN 220105
Practice locations
Addresses where Mark C. Nitzberg is enrolled with Medicare (CMS data updated 2026-10-02).
- 16 Keewaydin DrSalem, NH 03079 (603) 401‑6466
- 380 R Merrimack St, Suite 2cMethuen, MA 01844
- 411 Merrimack St, Suite 202Methuen, MA 01844 (978) 681‑1977
- 70 E StMethuen, MA 01844 (978) 687‑0151
Specialties
- Gastroenterologyprimary
- Internal Medicinealso
Other gastroenterologists in New Hampshire
Clinicians with the same Medicare primary specialty in New Hampshire — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Massachusetts Medical School |
| Graduation year | 1989 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1881652758 |
| 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