Quick answers
- Does Mark L. Gaynor accept Medicare assignment?
- Yes. Medicare's clinician data says Mark L. Gaynor accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
- What is Mark L. Gaynor's NPI number?
- 1275515009. 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 L. Gaynor is enrolled with Medicare (CMS data updated October 2, 2026).
- 100 Whitney AveNew Haven, CT 06510 (203) 865‑0865
Specialties
- Clinical Social Workerprimary
Find other clinicians: Clinical Social Worker, Connecticut →
Other clinical social workers in New Haven
Clinicians with the same Medicare primary specialty in New Haven, CT — not a recommendation.
Clinician information
| Credential | CSW |
|---|---|
| Graduation year | 1975 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1275515009 |
| 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 October 2, 2026, retrieved October 29, 2026
- 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