Tad Mark Johnson, MD
Allergy Physician · Janesville, WI
Tad Mark Johnson, MD is an allergy physician with a practice address in Janesville, Wisconsin, and NPI 1659339919, issued on May 3, 2006. Check the license (Wisconsin 25307, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Tad Mark Johnson
- Credential
- MD
- Primary taxonomy
- Allergy Physician 207KA0200X
- License number
- 25307 WI
Self-reported in NPPES; status is on the state search - Practice location
- 3524 E Milwaukee St, Janesville, WI 53546
- Phone
- (608) 756-7100
- Enumerated
- May 3, 2006
- Record last updated
- Sep 6, 2012 (not updated in 14 years: call before relying on the address or phone)
- Fax
- (608) 756-4700
- Medicaid IDs
- 1659339919 WI
30661900 WI - Entity
- Type 1 · individual
8 nearest allergy physician records → All 18 in Wisconsin → Look up another NPI →
Also registered at 3524 E Milwaukee St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Ryndon Bautista, M.D.Internal Medicine Physician1225230170
Verify Tad Mark Johnson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWisconsin Medical Examining Board
Search for license 25307Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average allergy physician in 2024
13 Medicare Part D claims, against an average of 750 among the 645 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Tad Mark Johnson among 18 allergy physician records in Wisconsin
Tad Mark Johnson, MD is one of 18 allergy physician records with a practice address in Wisconsin. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 6% of them.
- NPI issued2006 · 6% of these records are older, 33% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileNo · 61% of these records are
- Record last updated2012 · 72% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207KA0200X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy Physician providers in Wisconsin
There are 18 allergy physician records in Wisconsin.
All 18 in Wisconsin → Every provider in Janesville → Allergy Physician nationwide →
The 8 allergy physician records with the nearest ZIP codes
- Mark BiagtanMadison, WI 537151376707307
- Helen Sanderson, MDMadison, WI 537151699274670
- Ravi Viswanathan, MDMadison, WI 537171326084534
- Courtney GaberinoMadison, WI 537181689170979
- Ivana Surjancev, MDMadison, WI 537181801425814
- Robert Bush, MDMadison, WI 537921881660801
- Mark Moss, MDMadison, WI 537921093781163
- Gary Steven, M.D.Greenfield, WI 532281972530699
Common questions
What is Tad Mark Johnson, MD's NPI number?
Tad Mark Johnson, MD's National Provider Identifier (NPI) is 1659339919, issued on May 3, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Tad Mark Johnson, MD located?
The NPPES record lists a practice address at 3524 E Milwaukee St, Janesville, WI, 53546. Phone: (608) 756-7100. Providers update this record themselves, so call before visiting.
How can I verify Tad Mark Johnson, MD's license?
NPPES lists Wisconsin license number 25307, 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.
How much does Tad Mark Johnson, MD prescribe under Medicare Part D?
In 2024, Tad Mark Johnson, MD had 13 Medicare Part D claims; the average among allergy physician prescribers was 750. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
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.