MARGARET RYAN O'NEILL MD
NPI 1255918868
Obstetrics & Gynecology in Glastonbury, CT
About Margaret Ryan O'neill Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MARGARET RYAN O'NEILL MD (NPI 1255918868) is an individual obstetrics & gynecology provider in Glastonbury, Connecticut, licensed in Connecticut (083062) and active in the NPI registry since March 2021. She is enrolled in Medicare PECOS, maintains a secondary practice location in Hartford, and is a graduate of University Of Connecticut School Of Medicine (2021).
NPPES Registry Identity
Specialties & Licenses
Secondary Practice Location 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Margaret Ryan O'neill Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
2Medicare enrollment records show Margaret O'neill reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Hartford, CT 06102
- Reassigned Medicare billing, Connecticut enrollment
- 1,333 clinicians in this Medicare group
Rocky Hill, CT 06067
- Reassigned Medicare billing, Connecticut enrollment
- 371 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 06033 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 8
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
GLASTONBURY, CT 06033
GLASTONBURY, CT 06033
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Margaret O'neill's NPI number?
The NPI number for Margaret O'neill is 1255918868. It was assigned to this individual provider in the NPPES registry on March 28, 2021.
Where is Margaret O'neill located?
Margaret O'neill practices at 330 Western Blvd Ste 102, Glastonbury, CT 06033. The listed phone number is (860) 547-0306.
What is Margaret O'neill's specialty?
The primary specialty registered for this NPI is Obstetrics & Gynecology with taxonomy code 207V00000X.
Is Margaret O'neill enrolled in Medicare?
Yes. Margaret O'neill is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Margaret O'neill's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Margaret O'neill reassigns Medicare benefits to 2 organizations: Hartford Hospital (Hartford, CT) and Physicians For Women's Health LLC (Rocky Hill, CT). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Margaret O'neill's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Margaret O'neill accept?
Health plans from Anthem Blue Cross and Blue Shield list Margaret O'neill as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
When was this NPI record last updated?
The NPPES record for Margaret O'neill was last updated on September 30, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Margaret Ryan O'neill, MD · NPI 1255918868
Obstetrics & Gynecology physician in Glastonbury, Connecticut. Individual provider, active in the CMS NPPES registry since March 28, 2021.
## Identity
- **NPI:** 1255918868 (Entity type: Individual)
- **Enumerated:** March 28, 2021
- **Primary specialty:** Obstetrics & Gynecology · taxonomy 207V00000X
- **State license:** 083062 (Connecticut)
- **Sole proprietor:** No
## Practice location
- **Address:** 330 WESTERN BLVD STE 102, Glastonbury, CT 06033-4383
- **Phone:** (860) 547-0306
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): Hartford Hospital (NPI 1407806391, Hartford, CT); Physicians For Women's Health LLC (NPI 1801826680, Rocky Hill, CT) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** University Of Connecticut School Of Medicine, class of 2021
## Record status
- **NPPES last updated:** September 30, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1255918868) · Data from the CMS NPPES public registry.