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COLLEEN WALKER MD PLLC
NPI 1720549264
Internal Medicine in Louisville, KY

Active since March 27, 2019CLIA 18D2154996 · Waiver
3945 NANZ AVE, LOUISVILLE, KY 40207(502) 899-1100(502) 614-6508 Get Directions Write a Review

NPPES record last updated: March 27, 2019. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Colleen Walker Md Pllc NPPES

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

COLLEEN WALKER MD PLLC (NPI 1720549264) is a healthcare organization registered as an internal medicine in Louisville, Kentucky and active in the NPI registry since March 2019. The organization holds a CLIA Waiver certificate valid through September 20, 2028 and lists Colleen M Walker, Md Owner, as its authorized official.

NPPES Registry Identity

NPI1720549264
Entity TypeOrganization
Primary Taxonomy207R00000X
Legal Business NameCOLLEEN WALKER MD PLLC
Location Address3945 NANZ AVELouisville, KY 40207
Mailing Address3945 Nanz AveLouisville, KY 40207 · (502) 899-1100 · Fax (502) 614-6508
Phone(502) 899-1100
Fax(502) 614-6508
Organization SubpartNo
Authorized OfficialColleen M WalkerMd Owner · (502) 899-1100
Enumeration DateMarch 27, 2019
✔ NPI 1720549264 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
3945 NANZ AVE, Louisville, KY 40207
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Other Names 1

Other NameUltimate Md

Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Colleen Walker Md Pllc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

2

Medicare enrollment records show 2 clinicians reassign Medicare billing to Colleen Walker MD PLLC, which bills Medicare for the services they deliver. Of these, 1 practice at this address and 2 within 10 miles. They are listed nearest first.

Clinicians, nearest first (2)

Colleen Walker, MD
Internal Medicine
NPI 1750346078
3945 NANZ AVE
Louisville, KY 40207
(502) 899-1100
✔ PECOS✔ Accepts MedicareSame address
Diane Rennirt, M.D
Internal Medicine
NPI 1124083969
400 BLANKENBAKER PKWY STE 201
Louisville, KY 40243
(502) 713-0777
✔ PECOS✔ Accepts Medicare5.8 mi

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

CLIA Laboratory Certificates CMS CLIA

Laboratory certificates issued under the Clinical Laboratory Improvement Amendments (CLIA) program, which sets federal quality standards for human laboratory testing in the United States. There is no official CMS crosswalk between CLIA and NPI numbers; these certificates are associated with this NPI by matching facility names, locations and phone numbers in the CMS CLIA registry.

Certificate of Waiver 18D2154996

Colleen Walker, MD, PLLC · Louisville, KY
Active · expires Sep 20, 2028
CLIA Number18D2154996
Laboratory TypePhysician Office
Certificate Effective DateSeptember 21, 2026
Certificate Expiration DateSeptember 20, 2028
Laboratory DirectorMs. Colleen Walker
Laboratory Phone(502) 899-1100
Laboratory LocationColleen Walker, MD, PLLC3945 Nanz Ave, Louisville, KY 40207
CLIA data matches this NPI record on: Address Name Phone
This certificate is issued to a laboratory to perform only waived tests.

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 Colleen Walker MD PLLC's NPI number?

The NPI number for Colleen Walker MD PLLC is 1720549264. It was assigned to this organization in the NPPES registry on March 27, 2019. The provider is also known as Ultimate MD.

Where is Colleen Walker MD PLLC located?

Colleen Walker MD PLLC is located at 3945 Nanz Ave, Louisville, KY 40207. The listed phone number is (502) 899-1100.

What is Colleen Walker MD PLLC's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Colleen Walker MD PLLC enrolled in Medicare?

Yes. Colleen Walker MD PLLC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Colleen Walker MD PLLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 2 clinicians, all in Internal Medicine, reassign their Medicare billing to Colleen Walker MD PLLC. A 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 the clinician's services. Of these, 1 practice at this address and 2 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does Colleen Walker MD PLLC hold a CLIA laboratory certificate?

Yes. A Certificate of Waiver (number 18D2154996) is associated with this NPI, valid through September 20, 2028. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

When was this NPI record last updated?

The NPPES record for Colleen Walker MD PLLC was last updated on March 27, 2019. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 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.