NPIMap

Individual provider Active NPI

Nathaniel James Stewart, M.D.

  • Orthopaedic Surgery Physician
  • Altoona, WI
National Provider Identifier
1225064017
Registry record updated Jun 5, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Orthopaedic Surgery PhysicianTaxonomy code 207X00000X
License
39520 Issued in WI
Practice address
1200 Oakleaf Way Ste a
Altoona, WI 54720-2217
Phone
(715) 832-1400
Fax
(715) 832-4187
NPI assigned
Jun 23, 2006
Sex
Male
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Jun 5, 2026

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 1

Specialty (taxonomy)CodeLicenseStatePrimary
Orthopaedic Surgery Physician 207X00000X 39520 WI Primary

Addresses

Primary practice location

1200 Oakleaf Way Ste a
Altoona, WI 54720-2217

Mailing address

1200 Oakleaf Way Ste a
Altoona, WI 54720-2217
Phone (715) 832-1400

Other identifiers 9

IdentifierTypeStateIssuer
32400600MedicaidWI
85410OtherWISECURITY HEALTH PLAN
378L4STOtherWIBCBS MN
09 01123OtherWIMEDICA/SELECTCARE EC
1930920OtherWIUNITED HEALTHCARE
208036400OtherWIOWCP
P00136555OtherWIRAILROAD MEDICARE
09-01124OtherWIMEDICA/SELECTCARE CF
2110231OtherWIFIRST HEALTH

Electronic endpoints 1

TypeEndpointUseAffiliation
Direct Messaging Address njstewart@cvosm.gwaydirect.com

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in WI
Eligible to order & refer
  • Part B services
  • Medical equipment
  • Home health
  • Power mobility devices
  • Hospice
Green means eligible to order or refer.

Enrollment records 1

Enrollment IDStateProvider typePAC IDDetails
I20040619000068 WI Practitioner - Orthopedic Surgery 5799688099 Reassigns benefits to 1 organization

Care Compare profile

Medicare Care Compare
Specialty
Orthopedic Surgery
Education
University of Minnesota Medical School, 1992
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Group practices
Advantage Physical Therapy and Sports Rehab, LLCGroup PAC ID 8022016336, shared by 3 NPIs, 289 clinicians
Chippewa Valley Orthopedics and Sports Medicine Clinic SCGroup PAC ID 7618948399, 30 clinicians

Practice addresses (Care Compare)

112 Ash St
Suite a
Spooner, WI 54801-1487
Phone (715) 635-3979

1200 Oakleaf Way
A
Altoona, WI 54720-2245
Phone (715) 832-1400

Hospital & facility affiliations

  • Oakleaf Surgical Hospital Hospital, Altoona, WI, CCN 520196
  • Aspirus Stanley Hospital Hospital, Stanley, WI, CCN 521311
  • Aspirus Medford Hospital & Clinics, Inc Hospital, Medford, WI, CCN 521324
  • Cumberland Memorial Hospital Hospital, Cumberland, WI, CCN 521353
  • Marshfield Medical Center - Eau Claire Hospital, Eau Claire, WI, CCN 520210

Merit-based Incentive Payment System (MIPS)

Final score
22.45 of 100Reported as individual
Quality
0
Promoting interoperability
0
Improvement activities
0
Cost
74.83

Procedures performed for Medicare patients

ProcedureNumber of procedures
Hip replacement67
Knee replacement33
Lower limb (leg) arthroscopy (minimally invasive joint repair)1-10

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Doctor of Medicine

State licenses

LicenseStateTypeSpecialty
39520WIMDOrthopaedic Surgery Physician

Practice roles

OrganizationSpecialtyStatusNew patients
Chippewa Valley Orthopedics and Sports Medicine Clinic, SC CurrentSince Jul 1, 2004 Accepting new patients
Chippewa Valley Orthopedics and Sports Medicine Clinic SC Orthopaedic Surgery CurrentSince Jul 1, 2004 Accepting new patients
Flagstaff Medical Center Past Accepting new patients
Northern Arizona Orthopaedics, LTD. Past Accepting new patients
Medical X-Ray Consultants, LTD Past Accepting new patients

Locations

1200 Oakleaf Way
Ste A
Altoona, WI 54720
Phone (800) 322-1747

1200 Oakleaf Way
Altoona, WI 54720
Phone (715) 839-1778

757 Lakeland Dr
Ste B
Chippewa Falls, WI 54729
Phone (715) 723-5989

4212 Southtowne Dr
Eau Claire, WI 54701
Phone 71583214001108

900 W Clairemont Ave
Eau Claire, WI 54701
Phone (715) 717-4121

2200 Cedar Crest Dr
Ste A
Rice Lake, WI 54868
Phone (715) 455-0408

113 4th Ave
Shell Lake, WI 54871
Phone (715) 468-7833

Interoperability endpoints

  • Direct secure messaging: njstewart@cvosm.emadirect.md

Organizations & group practices 5

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

Hospital & facility affiliations 13

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

View all 13

NPI Registry JSON

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1151020800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1780617600000",
    "number": "1225064017",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1200 OAKLEAF WAY STE A",
            "city": "ALTOONA",
            "state": "WI",
            "postal_code": "547202217",
            "telephone_number": "715-832-1400",
            "fax_number": "715-832-4187"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1200 OAKLEAF WAY STE A",
            "city": "ALTOONA",
            "state": "WI",
            "postal_code": "547202217",
            "telephone_number": "715-832-1400",
            "fax_number": "715-832-4187"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "STEWART",
        "first_name": "NATHANIEL",
        "middle_name": "JAMES",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-06-23",
        "last_updated": "2026-06-05",
        "certification_date": "2026-06-05",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207X00000X",
            "taxonomy_group": "",
            "desc": "Orthopaedic Surgery",
            "state": "WI",
            "license": "39520",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "32400600",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "SECURITY HEALTH PLAN",
            "identifier": "85410",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "BCBS MN",
            "identifier": "378L4ST",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "MEDICA/SELECTCARE EC",
            "identifier": "09 01123",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "UNITED HEALTHCARE",
            "identifier": "1930920",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "OWCP",
            "identifier": "208036400",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "RAILROAD MEDICARE",
            "identifier": "P00136555",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "MEDICA/SELECTCARE CF",
            "identifier": "09-01124",
            "state": "WI"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "FIRST HEALTH",
            "identifier": "2110231",
            "state": "WI"
        }
    ],
    "endpoints": [
        {
            "endpointType": "DIRECT",
            "endpointTypeDescription": "Direct Messaging Address",
            "endpoint": "njstewart@cvosm.gwaydirect.com",
            "affiliation": "N",
            "address_1": "1200 OakLeaf Way",
            "address_2": "Suite A",
            "city": "Altoona",
            "state": "WI",
            "country_code": "US",
            "postal_code": "547202245",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "other_names": []
}

Other providers in Altoona, WI

Sources for this page

Verify at the official NPI Registry.