NPI Portal NPI Lookup & Verification

Mr. Matthew S. Bay, P.A.

Mr. Matthew S. Bay is a Surgical Physician Assistant provider (Physician Assistant) practicing in Appleton, WI, registered in the NPPES registry with NPI 1033359401 since 2009. The credential PA stands for Physician Assistant. Practices at Fox Valley Surgical Associates Ltd (listed at the same practice address in NPPES).

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NPI 1033359401
Entity type Individual (Type 1)
Name Mr. Matthew S. Bay
Credential P.A.
Sex Male
Practice address 2000 E MILESTONE DR, Appleton, WI, 54913
Phone 9207318131
Fax 9208320444
Enumeration date 2009-02-25
Last updated in NPPES 2026-01-05

Taxonomy & licenses

Taxonomy code Specialty Primary License State
363AS0400X Surgical Physician Assistant Primary 2387-23 WI

PA — Physician Assistant: A licensed clinician who practices medicine in collaboration with physicians, trained in a graduate PA program. About the PA credential

Copy-ready billing details
Provider: Matthew Bay, P.A.
NPI: 1033359401
Taxonomy: 363AS0400X (Surgical Physician Assistant)
Address: 2000 E MILESTONE DR, Appleton, WI, 54913

Other providers at this practice address

NPI Name Type Specialty Location
1659363802 Dean Sutton Individual Nurse Practitioner Appleton, WI
1285626465 Charles Cheng Individual Surgery Physician Appleton, WI
1902898182 Robert Ballard Individual Vascular Surgery Physician Appleton, WI
1528053758 Christopher Wagner Individual Surgery Physician Appleton, WI
1720036387 Michael Black Individual Surgery Physician Appleton, WI
1376594952 Fox Valley Surgical Associates Ltd Organization Surgery Physician Appleton, WI
1356378731 Christine Arendt Individual Nurse Practitioner Appleton, WI
1912155250 Eric Stanelle Individual Surgery Physician Appleton, WI

Verify this record

Cross-check NPI 1033359401 against the authoritative CMS record: view Mr. Matthew S. Bay on the official NPPES registry .

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty. Read the full guide or validate an NPI number.

Frequently asked questions

Is this the official NPI registry?
No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.
What specialty is Matthew Bay?
Matthew Bay is registered in NPPES with the primary taxonomy of Surgical Physician Assistant. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2026-01-05.