JOHN L OLSON MD
NPI 1194835249
Internal Medicine in Marshfield, WI
About John L Olson Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
JOHN L OLSON MD (NPI 1194835249) is an individual internal medicine provider in Marshfield, Wisconsin, licensed in Wisconsin (29284) and active in the NPI registry since August 2006. He is enrolled in Medicare PECOS.
NPPES Registry Identity
Specialties & Licenses
Other Identifiers 3
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
John L Olson Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
2Medicare enrollment records show John Olson reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Marshfield, WI 54449
- Reassigned Medicare billing, Wisconsin enrollment
- 2,540 clinicians in this Medicare group
Chetek, WI 54728
- Reassigned Medicare billing, Wisconsin enrollment
- 1,616 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.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 54449 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Referred Medical Equipment & Supplies CMS DME claims
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
MARSHFIELD, WI 54449
MARSHFIELD, WI 54449
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 John Olson's NPI number?
The NPI number for John Olson is 1194835249. It was assigned to this individual provider in the NPPES registry on August 30, 2006.
Where is John Olson located?
John Olson practices at 1000 N Oak Ave, Marshfield, WI 54449. The listed phone number is (715) 387-5755.
What is John Olson's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is John Olson enrolled in Medicare?
Yes. John Olson is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for John Olson's services?
According to the CMS Revalidation Reassignment List (October 2026 release), John Olson reassigns Medicare benefits to 2 organizations: Marshfield Clinic Inc (Marshfield, WI) and Lakeview Medical Center Inc Of Rice Lake (Chetek, 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 John Olson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for John Olson was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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.
# John L Olson, MD · NPI 1194835249
Internal Medicine physician in Marshfield, Wisconsin. Individual provider, active in the CMS NPPES registry since August 30, 2006.
## Identity
- **NPI:** 1194835249 (Entity type: Individual)
- **Enumerated:** August 30, 2006
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** 29284 (Wisconsin)
- **Sole proprietor:** No
## Practice location
- **Address:** 1000 N OAK AVE, Marshfield, WI 54449
- **Phone:** (715) 387-5755
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): Marshfield Clinic Inc (NPI 1952347981, Marshfield, WI); Lakeview Medical Center Inc Of Rice Lake (NPI 1659008605, Chetek, WI) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** July 8, 2007
- **Other identifiers:** Medicare UPIN E74139; Medicare ID-Type Unspecified 27672200 (WI); Medicaid 31520700 (WI)
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Source: [NPI Profile](https://npiprofile.com/npi/1194835249) · Data from the CMS NPPES public registry.