Quick answers
- Does Margaret R. O'Neill accept Medicare assignment?
- Yes. Medicare's clinician data says Margaret R. O'Neill 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 Margaret R. O'Neill's NPI number?
- 1255918868. 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 Margaret R. O'Neill is enrolled with Medicare (CMS data updated October 2, 2026).
- 100 Retreat Ave, Suite 700Hartford, CT 06106 (860) 547‑0306
- 103 Newtown Rd, Candlewood Center for Womens HealthDanbury, CT 06810 (203) 730‑8789
- 330 Western Blvd, 102 Womens Comprehensive Health CareGlastonbury, CT 06033 (860) 547‑0306
Group practices
Medicare enrollment lists Margaret R. O'Neill as a member of this group (CMS data updated October 2, 2026).
- Physicians for Women's Health, LLC318 clinicians in the group
Specialties
- Obstetrics/Gynecologyprimary
Other OB-GYNs in Hartford
Clinicians with the same Medicare primary specialty in Hartford, CT — not a recommendation.
Other clinicians in Physicians for Women's Health, LLC
Medicare enrollment lists these clinicians in the same group practice — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Connecticut School Of Medicine |
| Graduation year | 2021 (5 years since medical school) |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1255918868 |
| 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