Karl C. Larson, M.D.
Family Medicine Physician · Oshkosh, WI
Karl C. Larson, M.D. is a family medicine physician with a practice address in Oshkosh, Wisconsin, and NPI 1063528529, issued on Aug 21, 2006. Check the license (Wisconsin 28253, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Karl C. Larson
- Credential
- M.D.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 28253 WI
Self-reported in NPPES; status is on the state search - Practice location
- 2725 Jackson St, Oshkosh, WI 54901
- Phone
- (920) 223-7500
- Enumerated
- Aug 21, 2006
- Record last updated
- Dec 17, 2009 (not updated in 17 years: call before relying on the address or phone)
- Fax
- (920) 223-7630
- Medicaid ID
- 3076200 WI
- Medicare enrollment
- Enrolled (PECOS I20100111000375); accepts Medicare assignment
- Medical or professional school
- Medical College Of Wisconsin, 1981
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 3,765 in Wisconsin → Look up another NPI →
Also registered at 2725 Jackson St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Kelly Badger, MDFamily Medicine Physician1558523258
- Andrea Barribeau, ATAthletic Trainer1356323893
- Harold Boccheciamp, MDFamily Medicine Physician1063406973
- Matthew Husnik, LATAthletic Trainer1558544726
- Dawn MartinNurse Practitioner1952629941
- Amber Norka, LATAthletic Trainer1124016894
Verify Karl C. Larson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWisconsin Medical Examining Board
Search for license 28253Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
38% more Medicare Part D claims than the average family medicine physician in 2024
4,884 Medicare Part D claims for 497 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 10% of claims. 201 claims were for opioids.
Most prescribed
- Atorvastatin Calcium237 claims
- Losartan Potassium218 claims
- Amlodipine Besylate214 claims
- Rosuvastatin Calcium167 claims
- Lisinopril162 claims
- Metoprolol Succinate151 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 84.6 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Aspirus Rhinelander And Tomahawk Hospitals And Clinics, Inc.Wittenberg, WI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Karl C. Larson among 3,765 family medicine physician records in Wisconsin
Karl C. Larson, M.D. is one of 3,765 family medicine physician records with a practice address in Wisconsin. 75% 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 10% of them.
- NPI issued2006 · 10% of these records are older, 46% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 62% of these records are
- Graduated1981 · median 2007 among the 2,347 with a school on file
- Record last updated2009 · 56% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
52 family medicine physician records list a practice address in Oshkosh
They are 52 of the 1,527 NPPES records with a practice address in Oshkosh, and 3,765 family medicine physician records in Wisconsin.
All 3,765 in Wisconsin → Every provider in Oshkosh → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Kelly Badger, MDOshkosh, WI 549011558523258
- Kristin Beougher, DOOshkosh, WI 549011891704417
- Scott Beougher, DOOshkosh, WI 549011063421683
- Harold Boccheciamp, MDOshkosh, WI 549011063406973
- Eric Duwell, MDOshkosh, WI 549011710092978
- Shawn Ekstrom, MDOshkosh, WI 549011134120033
- Albert Fisher, MDOshkosh, WI 549011437131117
- George Lessmann, DOOshkosh, WI 549011134641384
Common questions
What is Karl C. Larson, M.D.'s NPI number?
Karl C. Larson, M.D.'s National Provider Identifier (NPI) is 1063528529, issued on Aug 21, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Karl C. Larson, M.D. located?
The NPPES record lists a practice address at 2725 Jackson St, Oshkosh, WI, 54901. Phone: (920) 223-7500. Providers update this record themselves, so call before visiting.
How can I verify Karl C. Larson, M.D.'s license?
NPPES lists Wisconsin license number 28253, 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 Karl C. Larson, M.D. prescribe under Medicare Part D?
In 2024, Karl C. Larson, M.D. had 4,884 Medicare Part D claims for 497 beneficiaries; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.
What is Karl C. Larson, M.D.'s MIPS final score?
The 2023 MIPS final score is 84.6 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.