Quick answers
- Which hospitals does Mark Chrostowski work at?
- Medicare's official clinician data lists Mark Chrostowski at 1 hospital: Greenwich Hospital Association -. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark Chrostowski see patients?
- Medicare's clinician data lists 1 practice location in Greenwich, CT. Call before your visit to confirm the address.
- What is Mark Chrostowski's specialty?
- Medicare lists Anesthesiology as the primary specialty.
- Does Mark Chrostowski accept Medicare assignment?
- Yes. Medicare's clinician data says Mark Chrostowski 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 Chrostowski?
- (203) 661-5330, as listed in official Medicare / NPI Registry data.
- What is Mark Chrostowski's NPI number?
- 1558317040. 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 Chrostowski works
Medicare's Facility Affiliation Data lists Mark Chrostowski at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Greenwich Hospital Association -Greenwich, CT · Acute Care Hospital · CCN 070018
Practice locations
Addresses where Mark Chrostowski is enrolled with Medicare (CMS data updated 2026-10-02).
- 5 Perryridge RdGreenwich, CT 06830 (203) 661‑5330
Group practices
Medicare enrollment lists Mark Chrostowski as a member of this group (CMS data updated 2026-10-02).
- Greenwich Anesthesiology Associates PC42 clinicians in the group
Specialties
- Anesthesiologyprimary
Other anesthesiologists in Greenwich
Clinicians with the same Medicare primary specialty in Greenwich, CT — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Js Weill Medical College, Cornell University |
| Graduation year | 2004 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1558317040 |
| 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