NPPES file of Aug 9, 2026

Thomas S. Hyzer, M.D.

Internal Medicine Physician · Madison, WI

Thomas S. Hyzer, M.D. is an internal medicine physician with a practice address in Madison, Wisconsin, and NPI 1174586499, issued on Apr 8, 2006. Check the license (Wisconsin 22599-020, as entered in NPPES) on the Wisconsin Medical Examining Board; the federal record below is the public data PlainDoctor holds for this provider.

Record from CMS NPPES, file of Aug 9, 2026 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1174586499
Name
Thomas S. Hyzer
Credential
M.D.
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
22599-020 WI
Self-reported in NPPES; status is on the state search
Practice location
4410 Regent St, Madison, WI 53705
Phone
(608) 233-9746
Enumerated
Apr 8, 2006
Record last updated
Jun 28, 2017 (not updated in 9 years: call before relying on the address or phone)
Medicaid ID
30274600 WI
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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8 nearest internal medicine physician records → All 2,078 in Wisconsin → Look up another NPI →

Also registered at 4410 Regent St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Thomas Ansfield, M.D.Internal Medicine Physician1700848538
  2. Casey Birschbach, MDInternal Medicine Physician1366005928
  3. Amy Buencamino, M.D.Pediatrics Physician1619939493
  4. Puneet Dhillon, M.D.Internal Medicine Physician1073855474
  5. Nicole Ertl, M.D.Pediatrics Physician1457664385
  6. John Ewalt, M.D.Internal Medicine Physician1518923283

Verify Thomas S. Hyzer in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersWisconsin Medical Examining Board
    Search for license 22599-020    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Wisconsin license search

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Thomas S. Hyzer among 2,078 internal medicine physician records in Wisconsin

Thomas S. Hyzer, M.D. is one of 2,078 internal medicine physician records with a practice address in Wisconsin. 70% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does not. Its NPI, issued in 2006, is newer than 9% of them.

  • NPI issued2006 · 9% of these records are older, 46% newer
  • In a Medicare fileNo · 70% of these records are
  • In the CMS Doctors and Clinicians fileNo · 53% of these records are
  • Record last updated2017 · 55% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

417 internal medicine physician records list a practice address in Madison

They are 417 of the 15,014 NPPES records with a practice address in Madison, and 2,078 internal medicine physician records in Wisconsin. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.

All 2,078 in Wisconsin → Every provider in Madison → Internal Medicine Physician nationwide →

The 8 internal medicine physician records with the nearest ZIP codes

  1. Joan Addington-White, MDMadison, WI 537051730142670
  2. Thomas Ansfield, M.D.Madison, WI 537051700848538
  3. Richard Dewitt, MDMadison, WI 537051386611010
  4. John Ewalt, M.D.Madison, WI 537051518923283
  5. Mary Feider, M.D.Madison, WI 537051376591537
  6. Michael Goldrosen, M.D.Madison, WI 537051952363541
  7. K Hla, MDMadison, WI 537051720054745
  8. Lisa Kaufman, MDMadison, WI 537051306828785

Common questions

What is Thomas S. Hyzer, M.D.'s NPI number?

Thomas S. Hyzer, M.D.'s National Provider Identifier (NPI) is 1174586499, issued on Apr 8, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Thomas S. Hyzer, M.D. located?

The NPPES record lists a practice address at 4410 Regent St, Madison, WI, 53705. Phone: (608) 233-9746. Providers update this record themselves, so call before visiting.

How can I verify Thomas S. Hyzer, M.D.'s license?

NPPES lists Wisconsin license number 22599-020, as entered by the provider. Search the Wisconsin Medical Examining Board at https://dsps.wi.gov/Pages/BoardsCouncils/MEB/Default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. An NPI identifies who bills; it is not a license.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.