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KATHERINE THERESA FLYNN-O'BRIEN M.D.
NPI 1225327398
Surgery - Pediatric Surgery in Milwaukee, WI

Active since March 29, 2011PECOS Enrolled
9000 W WISCONSIN AVE, MILWAUKEE, WI 53226(414) 266-6550(414) 266-6579 Get Directions Write a Review

NPPES record last updated: March 11, 2024. Verified against the NPPES registry weekly; last sync: November 01, 2026.

Record update history: Jul 11, 2023, Dec 3, 2021, Sep 17, 2020 (3 updates tracked since 2020).

About Katherine Theresa Flynn-o'brien M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

KATHERINE THERESA FLYNN-O'BRIEN M.D. (NPI 1225327398) is an individual pediatric surgery provider in Milwaukee, Wisconsin, licensed in Wisconsin (69080-20) and active in the NPI registry since March 2011. She is enrolled in Medicare PECOS and maintains 4 additional practice locations.

NPPES Registry Identity

NPI1225327398
Entity TypeIndividualFemale
Primary Taxonomy2086S0120X
Provider Legal NameKATHERINE THERESA FLYNN-O'BRIENCredential: M.D.
Location Address9000 W WISCONSIN AVEMilwaukee, WI 53226-4874
Mailing Address9000 W Wisconsin AveMilwaukee, WI 53226-4874 · (414) 266-6550 · Fax (414) 266-6579
Phone(414) 266-6550
Fax(414) 266-6579
Sole ProprietorNo
Enumeration DateMarch 29, 2011
Last NPPES UpdateMarch 11, 20243 updates tracked since enumeration
NPPES CertifiedMarch 11, 2024
✔ NPI 1225327398 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySurgery · Pediatric SurgeryAllopathic & Osteopathic Physicians
Taxonomy Code2086S0120X
License✔ Licensed in WI · 69080-20
Definition
A surgeon with expertise in the management of surgical conditions in premature and newborn infants, children and adolescents.
9000 W WISCONSIN AVE, Milwaukee, WI 53226
Open in Google Maps ↗

Secondary Practice Locations 4

Location 14855 S Moorland RdNew Berlin, WI 53151-7494 · Phone (414) 266-6550 · Fax (414) 266-6579
Location 21655 W Mequon RdMequon, WI 53092-3254 · Phone (414) 266-6550 · Fax (414) 266-6579
Location 33195 Hillside DrDelafield, WI 53018-2189 · Phone (414) 266-6550 · Fax (414) 266-6579
Location 49200 W Wisconsin AveMilwaukee, WI 53226-3522 · Phone (414) 805-5800 · Fax (414) 805-8097

Other Identifiers 1

Medicaid1225327398WI

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, Aspirus Health Plan, CareSource (Common Ground Healthcare) and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Katherine Theresa Flynn-o'brien M.d. is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

2

Medicare enrollment records show Katherine Flynn-o'brien reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Children's Specialty Group, Inc.
Same address
Pediatrics
9000 W WISCONSIN AVE
Milwaukee, WI 53226
  • Reassigned Medicare billing, Wisconsin enrollment
  • Medicare enrollment name: Childrens Specialty Group Inc
  • 424 clinicians in this Medicare group
NPI 1942970405 (414) 266-2000
The Medical College Of Wisconsin, Inc.
0.1 mi
Internal Medicine
8701 WATERTOWN PLANK RD
Milwaukee, WI 53226
  • Reassigned Medicare billing, Wisconsin enrollment
  • 3,983 clinicians in this Medicare group
NPI 1699720086 (414) 955-7101

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

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.

MS. LESLIE L. TALBERT NP
Nurse Practitioner (Pediatrics)
9000 W WISCONSIN AVE, PEDIATRIC CRITICAL CARE
MILWAUKEE, WI 53226
Milwaukee County (414) 266-3360
SARAH MARIE RUMLER DO
Pediatrics (Pediatric Hematology-Oncology)
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 955-4170
ALISON COREN
Pediatrics (Pediatric Endocrinology)
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 266-6750
BRANDON PALMER M.D.
Pediatrics
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 337-7050
AIDAN JAMES REID DO
Pediatrics
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 266-6800
KYNDAL LYN HETTICH RD, CSP, CD
Dietitian, Registered
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 266-5938
CARISA MARIE DIMATTINA LCSW
Social Worker (Clinical)
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 581-4004
BREYA LOGAN WHITEFIELD PHD
Psychologist (Clinical)
9000 W WISCONSIN AVE
MILWAUKEE, WI 53226
Milwaukee County (414) 266-2000

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 Katherine Flynn-o'brien's NPI number?

The NPI number for Katherine Flynn-o'brien is 1225327398. It was assigned to this individual provider in the NPPES registry on March 29, 2011.

Where is Katherine Flynn-o'brien located?

Katherine Flynn-o'brien practices at 9000 W Wisconsin Ave, Milwaukee, WI 53226. The listed phone number is (414) 266-6550.

What is Katherine Flynn-o'brien's specialty?

The primary specialty registered for this NPI is Surgery, specializing in Pediatric Surgery, with taxonomy code 2086S0120X.

Is Katherine Flynn-o'brien enrolled in Medicare?

Yes. Katherine Flynn-o'brien is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Katherine Flynn-o'brien's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Katherine Flynn-o'brien reassigns Medicare benefits to 2 organizations: Children's Specialty Group, Inc. (Milwaukee, WI) and The Medical College Of Wisconsin, Inc. (Milwaukee, WI). 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 Katherine Flynn-o'brien's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Katherine Flynn-o'brien accept?

Health plans from Anthem Blue Cross and Blue Shield, Aspirus Health Plan, CareSource (Common Ground Healthcare), HealthPartners and Network Health and 2 other insurers list Katherine Flynn-o'brien 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 Katherine Flynn-o'brien was last updated on March 11, 2024. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 2 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.