DR. THERESA R MAHON MD
NPI 1831256916
Obstetrics & Gynecology in Stamford, CT
About Dr. Theresa R Mahon Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. THERESA R MAHON MD (NPI 1831256916) is an individual obstetrics & gynecology provider in Stamford, Connecticut, licensed in New York (216249) and active in the NPI registry since January 2007. She is enrolled in Medicare PECOS and is a graduate of Albert Einstein College Of Medicine Of Yeshiva University (1996).
NPPES Registry Identity
Specialties & Licenses
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
Dr. Theresa R Mahon 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 Theresa Mahon reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Stamford, CT 06907
- Reassigned Medicare billing, Connecticut enrollment
- 496 clinicians in this Medicare group
Greenville, SC 29607
- Reassigned Medicare billing, Connecticut enrollment
- 37 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 06902 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
STAMFORD, CT 06902
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 Theresa Mahon's NPI number?
The NPI number for Theresa Mahon is 1831256916. It was assigned to this individual provider in the NPPES registry on January 2, 2007.
Where is Theresa Mahon located?
Theresa Mahon practices at 1 Hospital Plz, Stamford, CT 06902. The listed phone number is (203) 276-2030.
What is Theresa Mahon's specialty?
The primary specialty registered for this NPI is Obstetrics & Gynecology with taxonomy code 207V00000X.
Is Theresa Mahon enrolled in Medicare?
Yes. Theresa Mahon 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 Theresa Mahon's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Theresa Mahon reassigns Medicare benefits to 2 organizations: Stamford Health Medical Group Inc (Stamford, CT) and Obhg Connecticut PC (Greenville, SC). 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 Theresa Mahon's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Theresa Mahon was last updated on January 16, 2023. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 years 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.
# Dr. Theresa R Mahon, MD · NPI 1831256916
Obstetrics & Gynecology physician in Stamford, Connecticut. Individual provider, active in the CMS NPPES registry since January 2, 2007.
## Identity
- **NPI:** 1831256916 (Entity type: Individual)
- **Enumerated:** January 2, 2007
- **Primary specialty:** Obstetrics & Gynecology · taxonomy 207V00000X
- **State license:** 216249 (New York)
- **Sole proprietor:** No
## Practice location
- **Address:** 1 HOSPITAL PLZ, Stamford, CT 06902-3602
- **Phone:** (203) 276-2030 · **Fax:** (203) 276-7908
## 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): Stamford Health Medical Group Inc (NPI 1154633980, Stamford, CT); Obhg Connecticut PC (NPI 1861985129, Greenville, SC) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Albert Einstein College Of Medicine Of Yeshiva University, class of 1996
## Record status
- **NPPES last updated:** January 16, 2023
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Source: [NPI Profile](https://npiprofile.com/npi/1831256916) · Data from the CMS NPPES public registry.