ALEXANDRA B KIEFER MD
NPI 1689107641
Obstetrics & Gynecology in Stony Brook, NY
About Alexandra B Kiefer Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
ALEXANDRA B KIEFER MD (NPI 1689107641) is an individual obstetrics & gynecology provider in Stony Brook, New York, licensed in New York (315865) and active in the NPI registry since April 2017. She is enrolled in Medicare PECOS, is affiliated with John T Mather Memorial Hospital Of Port Jefferson, and is a graduate of Other (2018).
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
Alexandra B Kiefer 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 Reassignment
Medicare enrollment records show Alexandra Kiefer reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Stony Brook, NY 11794
- Reassigned Medicare billing, New York enrollment
- 125 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.
Areas of Expertise CMS Part B claims 3
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Hospital Affiliations CMS Care Compare 2
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
John T Mather Memorial Hospital Of Port Jefferson
Acute Care Hospitals · Port Jefferson, NYSuny/Stony Brook University Hospital
Acute Care Hospitals · Stony Brook, NYPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 11794 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.
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 Alexandra Kiefer's NPI number?
The NPI number for Alexandra Kiefer is 1689107641. It was assigned to this individual provider in the NPPES registry on April 6, 2017.
Where is Alexandra Kiefer located?
Alexandra Kiefer practices at 101 Nicolls R Obgyn Dept Hsc Level 9, Stony Brook, NY 11794. The listed phone number is (631) 444-4686.
What is Alexandra Kiefer's specialty?
The primary specialty registered for this NPI is Obstetrics & Gynecology with taxonomy code 207V00000X.
Is Alexandra Kiefer enrolled in Medicare?
Yes. Alexandra Kiefer 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 organization bills Medicare for Alexandra Kiefer's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Alexandra Kiefer reassigns Medicare benefits to University Associates In Obstetrics & Gynecology, University Faculty P (Stony Brook, NY). The 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 Alexandra Kiefer's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
Is Alexandra Kiefer affiliated with any hospitals?
According to CMS data, Alexandra Kiefer is affiliated with John T Mather Memorial Hospital Of Port Jefferson and Suny/Stony Brook University Hospital.
When was this NPI record last updated?
The NPPES record for Alexandra Kiefer was last updated on May 8, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Alexandra B Kiefer, MD · NPI 1689107641
Obstetrics & Gynecology physician in Stony Brook, New York. Individual provider, active in the CMS NPPES registry since April 6, 2017.
## Identity
- **NPI:** 1689107641 (Entity type: Individual)
- **Enumerated:** April 6, 2017
- **Primary specialty:** Obstetrics & Gynecology · taxonomy 207V00000X
- **State license:** 315865 (New York)
- **Sole proprietor:** No
## Practice location
- **Address:** 101 NICOLLS R OBGYN DEPT HSC LEVEL 9, Stony Brook, NY 11794-0001
- **Phone:** (631) 444-4686
## 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:** University Associates In Obstetrics & Gynecology, University Faculty P (NPI 1538114723, Stony Brook, NY), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2018
## Record status
- **NPPES last updated:** May 8, 2022
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Source: [NPI Profile](https://npiprofile.com/npi/1689107641) · Data from the CMS NPPES public registry.