Maria L. Fassari, MD
Internal Medicine Physician · Janesville, WI
Maria L. Fassari, MD is an internal medicine physician with a practice address in Janesville, Wisconsin, and NPI 1295860500, issued on Feb 23, 2007. Check the license (Wisconsin 67628-20, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Maria L. Fassari
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- 67628-20 WI
036-116724 IL
Self-reported in NPPES; status is on the state search - Practice location
- 3400 E Racine St, Janesville, WI 53546
- Phone
- (608) 373-8000
- Enumerated
- Feb 23, 2007
- Record last updated
- Nov 12, 2020 (not updated in 6 years: call before relying on the address or phone)
- Fax
- (608) 373-8514
- Medicaid ID
- 1295860500 WI
- Medicare enrollment
- Enrolled (PECOS I20070601000495); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,078 in Wisconsin → Look up another NPI →
Also registered at 3400 E Racine St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Maria L. Fassari in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWisconsin Medical Examining Board
Search for license 67628-20Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
91% fewer Medicare Part D claims than the average internal medicine physician in 2024
286 Medicare Part D claims for 148 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 35 claims were for opioids.
Most prescribed
- Amoxicillin-Clavulanate Potass20 claims
- Hydrocodone-Acetaminophen20 claims
- Prednisone16 claims
- Eliquis12 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.
Bills Medicare through one group practice
- Endeavor Health Medical GroupElmhurst, IL
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Maria L. Fassari among 2,078 internal medicine physician records in Wisconsin
Maria L. Fassari, MD 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. Its NPI, issued in 2007, is newer than 54% of them.
- NPI issued2007 · 54% of these records are older, 40% newer
- In a Medicare fileYes · 70% of these records are
- In the CMS Doctors and Clinicians fileYes · 53% of these records are
- Graduated2015 · median 2002 among the 1,098 with a school on file
- Record last updated2020 · 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).
22 internal medicine physician records list a practice address in Janesville
They are 22 of the 1,538 NPPES records with a practice address in Janesville, and 2,078 internal medicine physician records in Wisconsin.
All 2,078 in Wisconsin → Every provider in Janesville → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Mark Angevine, MDJanesville, WI 535461861586422
- Kristine Arndt, MDJanesville, WI 535461720442809
- Ryndon Bautista, M.D.Janesville, WI 535461225230170
- Nader Honarkhah, MDJanesville, WI 535461851464242
- Hena Kausar, M.DJanesville, WI 535461821418583
- Kauseruzzaman Khan, MDJanesville, WI 535461093724304
- Kathryn Lilley, MDJanesville, WI 535461104872670
- Dale Miller, MDJanesville, WI 535461932148491
Common questions
What is Maria L. Fassari, MD's NPI number?
Maria L. Fassari, MD's National Provider Identifier (NPI) is 1295860500, issued on Feb 23, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Maria L. Fassari, MD located?
The NPPES record lists a practice address at 3400 E Racine St, Janesville, WI, 53546. Phone: (608) 373-8000. Providers update this record themselves, so call before visiting.
How can I verify Maria L. Fassari, MD's license?
NPPES lists Wisconsin license number 67628-20, 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 Maria L. Fassari, MD prescribe under Medicare Part D?
In 2024, Maria L. Fassari, MD had 286 Medicare Part D claims for 148 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.