Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Matthew J Howenstein, M.D.

Vascular & Interventional Radiology Physician in Grafton, WI · enumerated 2008 · practices at Aurora Medical Center Grafton.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1548419336

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Dr. Matthew J Howenstein

Credential M.D.

Sex Male

Practice address 975 Port Washington Rd, Grafton, WI, 53024

Phone (414) 358-5420

Enumeration date Sep 16, 2008

Last updated in NPPES Aug 10, 2023

Taxonomy & licenses

2085R0202X Diagnostic Radiology Physician Allopathic & Osteopathic Physicians · License 61674 (WI) Secondary

2085R0202X Diagnostic Radiology Physician Allopathic & Osteopathic Physicians · License 036119267 (IL) Secondary

2085R0204X Vascular & Interventional Radiology Physician Allopathic & Osteopathic Physicians · License 61674 (WI) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
100035569	Medicaid	WI	-

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 → Validate an NPI →

Frequently asked questions

What is the NPI number for Matthew Howenstein?

The National Provider Identifier (NPI) for Matthew Howenstein is 1548419336, a Type 1 (individual) record in the CMS NPPES registry.

Where does Matthew Howenstein practice?

The practice location on file with NPPES is in Grafton, WI. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

Browse all →

Robert Fish Anesthesiology Physician · Grafton, WI NPI 1942292610 Laurie Williams Nurse Practitioner · Grafton, WI NPI 1982695136 Thomas Zukowski Hematology & Oncology Physician · Grafton, WI NPI 1912989260 Igor Levin Anesthesiology Physician · Grafton, WI NPI 1376527895 Ali Sadeghi Anesthesiology Physician · Grafton, WI NPI 1114901345 Chad Vanden Heuvel Anesthesiology Physician · Grafton, WI NPI 1467436444 Michael Erickson Surgery Physician · Grafton, WI NPI 1497732408 Harjot Sidhu Gastroenterology Physician · Grafton, WI NPI 1902885924

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2023-08-10.