NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Thomas J Carlson, MD

Surgery Physician in Fond Du Lac, WI · enumerated 2005.

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

National Provider Identifier

1831175546

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name Thomas J Carlson
Credential MD
Sex Male
Practice address 145 N Main St, Fond Du Lac, WI, 54935
Enumeration date Dec 15, 2005
Last updated in NPPES Nov 6, 2007

Taxonomy & licenses

208600000X Surgery Physician Allopathic & Osteopathic Physicians · License 15778 (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
12581 Other WI DEAN
31081500 Medicaid WI -
WI0148 Other WI JOHN DEERE

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 Thomas Carlson?
The National Provider Identifier (NPI) for Thomas Carlson is 1831175546, a Type 1 (individual) record in the CMS NPPES registry.
Where does Thomas Carlson practice?
The practice location on file with NPPES is in Fond Du Lac, WI. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-11-06.