BASE OF THE BAYS DERMATOLOGY PC
NPI 1538263231
Dermatology - Pediatric Dermatology in Williamsburg, MI

Q: What is Base Of The Bays Dermatology PC's NPI number?

The NPI number for Base Of The Bays Dermatology PC is 1538263231. It was assigned to this organization in the NPPES registry on September 12, 2006. The provider is doing business as M.D. Saunders, M.D., P.C..

Q: What is Base Of The Bays Dermatology PC's specialty?

The primary specialty registered for this NPI is Dermatology, specializing in Pediatric Dermatology, with taxonomy code 207NP0225X.

Active since September 12, 2006CLIA 23D0858935 · Certificate of Compliance

3950 SHORE RD, WILLIAMSBURG, MI 49690(231) 938-7004(231) 938-3112 Get Directions Write a Review

NPPES record last updated: September 11, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Sep 11, 2025, Aug 22, 2020 (2 updates tracked since 2020).

On this page

About Base Of The Bays Dermatology Pc NPPES

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

BASE OF THE BAYS DERMATOLOGY PC (NPI 1538263231), doing business as M.d. Saunders, M.d., P.c., is a healthcare organization registered as a pediatric dermatology in Williamsburg, Michigan and active in the NPI registry since September 2006. The organization holds a CLIA Certificate of Compliance certificate valid through September 12, 2028 and lists Mark Daniel Saunders, President, as its authorized official.

NPPES Registry Identity

NPI1538263231

Entity TypeOrganization

Primary Taxonomy207NP0225X

Legal Business NameBASE OF THE BAYS DERMATOLOGY PC

Location Address3950 SHORE RDWilliamsburg, MI 49690

Mailing Address3950 Shore RdWilliamsburg, MI 49690 · (231) 938-7004 · Fax (231) 938-3112

Phone(231) 938-7004

Fax(231) 938-3112

Organization SubpartNo

Authorized OfficialMark Daniel SaundersPresident · (231) 938-3112

Enumeration DateSeptember 12, 2006

Last NPPES UpdateSeptember 11, 20252 updates tracked since enumeration

✔ NPI 1538263231 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 5

★ Primary SpecialtyDermatology · Pediatric DermatologyAllopathic & Osteopathic Physicians

Taxonomy Code207NP0225X

License✔ Licensed in MI · MS051504

Definition

A pediatric dermatologist has, through additional special training, developed expertise in the treatment of specific skin disease categories with emphasis on those diseases which predominate in infants, children and adolescents.

Also ListedDermatologyTaxonomy 207N00000X · License MS051504 (MI)

Also ListedDermatology · MOHS-Micrographic SurgeryTaxonomy 207ND0101X · License MS051504 (MI)

Also ListedDermatology · DermatopathologyTaxonomy 207ND0900X · License MS051504 (MI)

Also ListedDermatology · Procedural DermatologyTaxonomy 207NS0135X · License MS051504 (MI)

3950 SHORE RD, Williamsburg, MI 49690

Open in Google Maps ↗

Other Names 1

Doing Business AsM.d. Saunders, M.d., P.c.

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

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Base Of The Bays Dermatology Pc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to Base Of The Bays Dermatology PC, which bills Medicare for the services this clinician delivers.

Clinician (1)

Mark Saunders, M.D.

Dermatology

NPI 1205922044

3950 SHORE RD
Williamsburg, MI 49690

(231) 938-7004

✔ PECOS✔ Accepts Medicare0.1 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 of Compliance 23D0858935

Base Of The Bays Dermatology, PC · Williamsburg, MI

Active · expires Sep 12, 2028

CLIA Number23D0858935

Laboratory TypePhysician Office

Certificate Effective DateSeptember 13, 2026

Certificate Expiration DateSeptember 12, 2028

Laboratory DirectorMark D. Saunders

Laboratory Phone(231) 938-7004

Laboratory LocationBase Of The Bays Dermatology, PC3950 Shore Road, Williamsburg, MI 49690

CLIA data matches this NPI record on: Address Name Phone

This certificate is issued to a laboratory after an inspection that finds the laboratory to be in compliance with all applicable CLIA requirements.

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 Base Of The Bays Dermatology PC's NPI number?

The NPI number for Base Of The Bays Dermatology PC is 1538263231. It was assigned to this organization in the NPPES registry on September 12, 2006. The provider is doing business as M.D. Saunders, M.D., P.C..

Where is Base Of The Bays Dermatology PC located?

Base Of The Bays Dermatology PC is located at 3950 Shore Rd, Williamsburg, MI 49690. The listed phone number is (231) 938-7004.

What is Base Of The Bays Dermatology PC's specialty?

The primary specialty registered for this NPI is Dermatology, specializing in Pediatric Dermatology, with taxonomy code 207NP0225X.

Is Base Of The Bays Dermatology PC enrolled in Medicare?

Yes. Base Of The Bays Dermatology PC is registered in the Medicare PECOS enrollment system.

How many clinicians bill Medicare through Base Of The Bays Dermatology PC?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Dermatology) reassigns their Medicare billing to Base Of The Bays Dermatology PC. 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. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Does Base Of The Bays Dermatology PC hold a CLIA laboratory certificate?

Yes. A Certificate of Compliance (number 23D0858935) is associated with this NPI, valid through September 12, 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 Base Of The Bays Dermatology PC was last updated on September 11, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months 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.