KARL C LARSON M.D.
NPI 1063528529
Family Medicine in Oshkosh, WI
About Karl C Larson M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
KARL C LARSON M.D. (NPI 1063528529) is an individual family medicine provider in Oshkosh, Wisconsin, licensed in Wisconsin (28253) and active in the NPI registry since August 2006. He is enrolled in Medicare PECOS, is affiliated with Aspirus Ironwood Hospital, and is a graduate of Medical College Of Wisconsin (1981).
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 8
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Karl C Larson M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
3Medicare enrollment records show Karl Larson reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Neenah, WI 54956
- Reassigned Medicare billing, Wisconsin enrollment
- 444 clinicians in this Medicare group
Iola, WI 54945
- Reassigned Medicare billing, Wisconsin enrollment
- 935 clinicians in this Medicare group
Woodruff, WI 54568
- Reassigned Medicare billing, Wisconsin enrollment
- Medicare enrollment name: Howard Young Medical Center Inc Of Woodruff Wisconsin
- 358 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Hospital Affiliations CMS Care Compare 5
Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.
Aspirus Ironwood Hospital
Critical Access Hospitals · Ironwood, MIAspirus Rhinelander Hospital
Acute Care Hospitals · Rhinelander, WIAspirus Wausau Hospital
Acute Care Hospitals · Wausau, WIHoward Young Medical Center
Acute Care Hospitals · Woodruff, WIAspirus Eagle River Hospital
Critical Access Hospitals · Eagle River, WIPhysician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 54901 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Other Providers at the Same Location NPPES 11
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
OSHKOSH, WI 54901
OSHKOSH, WI 54901
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Karl Larson's NPI number?
The NPI number for Karl Larson is 1063528529. It was assigned to this individual provider in the NPPES registry on August 21, 2006.
Where is Karl Larson located?
Karl Larson practices at 2725 Jackson St, Oshkosh, WI 54901. The listed phone number is (920) 223-7500.
What is Karl Larson's specialty?
The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.
Is Karl Larson enrolled in Medicare?
Yes. Karl Larson is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Karl Larson's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Karl Larson reassigns Medicare benefits to 3 organizations: Ascension Medical Group-Fox Valley Wisconsin, Inc (Neenah, WI), Aspirus Rhinelander & Tomahawk Hospitals & Clinics, Inc. (Iola, WI) and The Howard Young Medical Center, Inc. (Woodruff, WI). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Karl Larson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Karl Larson accept?
Health plans from Anthem Blue Cross and Blue Shield, Aspirus Health Plan, HealthPartners and Security Health Plan list Karl Larson as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
Is Karl Larson affiliated with any hospitals?
According to CMS data, Karl Larson is affiliated with Aspirus Ironwood Hospital, Aspirus Rhinelander Hospital, Aspirus Wausau Hospital, Howard Young Medical Center and Aspirus Eagle River Hospital.
When was this NPI record last updated?
The NPPES record for Karl Larson was last updated on December 17, 2009. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 16 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Karl C Larson, M.D. · NPI 1063528529
Family Medicine physician in Oshkosh, Wisconsin. Individual provider, active in the CMS NPPES registry since August 21, 2006.
## Identity
- **NPI:** 1063528529 (Entity type: Individual)
- **Enumerated:** August 21, 2006
- **Primary specialty:** Family Medicine · taxonomy 207Q00000X
- **State license:** 28253 (Wisconsin)
- **Sole proprietor:** No
## Practice location
- **Address:** 2725 JACKSON ST, Oshkosh, WI 54901-1513
- **Phone:** (920) 223-7500 · **Fax:** (920) 223-7630
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 3 organizations under Medicare reassignment (form CMS-855R): Ascension Medical Group-Fox Valley Wisconsin, Inc (NPI 1730126392, Neenah, WI); Aspirus Rhinelander & Tomahawk Hospitals & Clinics, Inc. (NPI 1578232849, Iola, WI); The Howard Young Medical Center, Inc. (NPI 1134183171, Woodruff, WI) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Medical College Of Wisconsin, class of 1981
## Record status
- **NPPES last updated:** December 17, 2009
- **Other identifiers:** Other 710016 (WI); Medicare UPIN A02401; Other 080113126 (WI); and 5 more
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Source: [NPI Profile](https://npiprofile.com/npi/1063528529) · Data from the CMS NPPES public registry.