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WEST MICHIGAN NEPHROLOGY PLLC
NPI 1235143090
Internal Medicine - Nephrology in Muskegon, MI

Active since July 28, 2006CLIA 23D0379906 · Microscopy
1250 MERCY DR, SUITE 101, MUSKEGON, MI 49444(231) 733-1912(231) 737-4603 Get Directions Write a Review

NPPES record last updated: July 9, 2020. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Jul 9, 2020, Mar 14, 2017 (2 updates tracked since 2017).

About West Michigan Nephrology Pllc NPPES

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

WEST MICHIGAN NEPHROLOGY PLLC (NPI 1235143090) is a healthcare organization registered as a nephrology in Muskegon, Michigan and active in the NPI registry since July 2006. The organization holds a CLIA Microscopy certificate valid through March 16, 2028 and lists Kathy Holtz, Practice Administrator, as its authorized official.

NPPES Registry Identity

NPI1235143090
Entity TypeOrganization
Primary Taxonomy207RN0300X
Legal Business NameWEST MICHIGAN NEPHROLOGY PLLC
Location Address1250 MERCY DR, SUITE 101Muskegon, MI 49444-1881
Mailing Address1250 Mercy Dr, Suite 101Muskegon, MI 49444-1881 · (231) 733-1912 · Fax (231) 737-4603
Phone(231) 733-1912
Fax(231) 737-4603
Organization SubpartNo
Authorized OfficialKathy HoltzPractice Administrator · (231) 733-1912
Enumeration DateJuly 28, 2006
Last NPPES UpdateJuly 9, 20202 updates tracked since enumeration
NPPES CertifiedJuly 9, 2020
✔ NPI 1235143090 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal Medicine · NephrologyAllopathic & Osteopathic Physicians
Taxonomy Code207RN0300X
Definition
An internist who treats disorders of the kidney, high blood pressure, fluid and mineral balance and dialysis of body wastes when the kidneys do not function. This specialist consults with surgeons about kidney transplantation.
1250 MERCY DR, Muskegon, MI 49444
Open in Google Maps ↗

Group Practice 1

Group TaxonomyThis provider is a business group of one or more individual practitioners, who practice with different areas of specialization.193200000X MULTI-SPECIALTY GROUP

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Blue Care Network of Michigan, Blue Cross Blue Shield of Michigan Mutual Insurance Company.Insurance ›

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

West Michigan Nephrology Pllc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Medicare Revalidation Due Date

Revalidation due by December 31, 2026

Medicare-enrolled providers and suppliers confirm their enrollment information with CMS on a set cycle, every 5 years for most and every 3 years for medical equipment suppliers. CMS sets the due date for each enrollment.

StateEnrollment IDDue date
StateMichiganEnrollment IDO20031212000848Non-DME Part B · Clinic/Group PracticeDue dateDecember 31, 2026
Source: CMS Revalidation Due Date List, October 2026 release.

Clinicians Billing Medicare Through This Organization

10

Medicare enrollment records show 10 clinicians reassign Medicare billing to West Michigan Nephrology PLLC, which bills Medicare for the services they deliver. Of these, 6 practice at this address and 10 within 10 miles. They are listed nearest first.

Clinicians by Medicare Specialty 2

Nephrology7
Nurse Practitioner3

Clinicians, nearest first (10)

Emily Conley, M.D.
Nephrology
NPI 1891753224
1250 MERCY DR STE 101
Muskegon, MI 49444
(231) 733-1912
✔ PECOS✔ Accepts MedicareSame address
James Conley, M.D.
Nephrology
NPI 1639137086
1250 MERCY DR STE 101
Muskegon, MI 49444
(231) 733-1912
✔ PECOS✔ Accepts MedicareSame address
Gregory Downer, M.D.
Nephrology
NPI 1285635367
1250 MERCY DR SUITE 101
Muskegon, MI 49444
(231) 733-1912
✔ PECOS✔ Accepts MedicareSame address
Joseph Mckenna, M.D.
Nephrology
NPI 1760411599
1250 MERCY DR STE 101
Muskegon, MI 49444
(231) 733-1912
✔ PECOS✔ Accepts MedicareSame address
Randall Muir, D.O
Nephrology
NPI 1942620521
1250 MERCY DR STE 101
Muskegon, MI 49444
(231) 733-1912
✔ PECOS✔ Accepts MedicareSame address
Mark Staniforth, MD
Nephrology
NPI 1619978707
1250 MERCY DR STE 101
Muskegon, MI 49444
(231) 739-6375
✔ PECOS✔ Accepts MedicareSame address
Bao Min Twu, MD
Nephrology
NPI 1356342448
1277 MERCY DR
Muskegon, MI 49444
(231) 733-1912
✔ PECOS0.1 mi
Amber Vanderwagen, AGACNP-BC
Nurse Practitioner
NPI 1508321662
1223 MERCY DR
Muskegon, MI 49444
(231) 672-3500
✔ PECOS✔ Accepts Medicare0.1 mi
Heather Dunn, FNP-C
Nurse Practitioner
NPI 1902342298
1500 E SHERMAN BLVD
Muskegon, MI 49444
(231) 672-3027
✔ PECOS✔ Accepts Medicare0.2 mi
Renee Mulder, FNP-C
Nurse Practitioner
NPI 1487314597
WEST MICHIGAN NEPHROLOGY PLLC 1250 MERCY DRIVE SUITE 101
Muskegon, MI 49444
(231) 733-1912
✔ PECOS✔ Accepts Medicare2.1 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 for Provider-Performed Microscopy Procedures (PPMP) 23D0379906

West Michigan Nephrology PLLC · Muskegon, MI
Active · expires Mar 16, 2028
CLIA Number23D0379906
Laboratory TypePhysician Office
Certificate Effective DateMarch 17, 2026
Certificate Expiration DateMarch 16, 2028
Laboratory DirectorGregory H. Downer
Laboratory Phone(231) 733-1912
Laboratory LocationWest Michigan Nephrology PLLC1250 Mercy Drive, Ste 101, Muskegon, MI 49444
CLIA data matches this NPI record on: Address Name Phone
This certificate is issued to a laboratory in which a physician, midlevel practitioner or dentist performs no tests other than the microscopy procedures. This certificate permits the laboratory to also perform 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 West Michigan Nephrology PLLC's NPI number?

The NPI number for West Michigan Nephrology PLLC is 1235143090. It was assigned to this organization in the NPPES registry on July 28, 2006.

Where is West Michigan Nephrology PLLC located?

West Michigan Nephrology PLLC is located at 1250 Mercy Dr Suite 101, Muskegon, MI 49444. The listed phone number is (231) 733-1912.

What is West Michigan Nephrology PLLC's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Nephrology, with taxonomy code 207RN0300X.

Is West Michigan Nephrology PLLC enrolled in Medicare?

Yes. West Michigan Nephrology PLLC is registered in the Medicare PECOS enrollment system.

When is West Michigan Nephrology PLLC's Medicare revalidation due?

According to the CMS Revalidation Due Date List (October 2026 release), the Medicare Non-DME Part B enrollment for this organization (Michigan, Clinic/Group Practice) is due for revalidation by December 31, 2026. Medicare providers and suppliers revalidate their enrollment every 5 years, and medical equipment suppliers every 3 years. Confirm current requirements with your Medicare Administrative Contractor.

How many clinicians bill Medicare through West Michigan Nephrology PLLC?

According to the CMS Revalidation Reassignment List (October 2026 release), 10 clinicians in 2 Medicare specialties reassign their Medicare billing to West Michigan Nephrology 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. The largest specialties are Nephrology (7) and Nurse Practitioner (3). Of these, 6 practice at this address and 10 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does West Michigan Nephrology PLLC hold a CLIA laboratory certificate?

Yes. A Certificate for Provider-Performed Microscopy Procedures (PPMP) (number 23D0379906) is associated with this NPI, valid through March 16, 2028. CLIA certificates authorize laboratory testing under the federal Clinical Laboratory Improvement Amendments program.

What insurance does West Michigan Nephrology PLLC accept?

Health plans from Blue Care Network of Michigan and Blue Cross Blue Shield of Michigan Mutual Insurance Company list West Michigan Nephrology PLLC 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 West Michigan Nephrology PLLC was last updated on July 9, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 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.