Gregory Wayne Grzesik, D.O.

Primary specialty

Hospitalist PhysicianTaxonomy code 208M00000X

License

65797 Issued in WI

Practice address

3400 Ministry Pkwy
Weston, WI 54476-5220

Phone

(715) 393-1220

NPI assigned

Jul 18, 2013

Sex

Male

Sole proprietor

No

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

Specialties & licenses 3

Addresses

Electronic endpoints 1

Medicare fee-for-service enrollment

Enrolled in WI

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: No
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 1

Specialty

Hospitalist

Education

Lake Erie College of Osteopathic Medicine, Erie, 2013

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

MCHS Hospitals IncGroup PAC ID 5698071173, shared by 28 NPIs, 1,195 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Marshfield Medical Center - Weston Hospital, Weston, WI, CCN 520202
• Marshfield Medical Center - Rice Lake Hospital, Rice Lake, WI, CCN 520011
• Marshfield Medical Center Hospital, Marshfield, WI, CCN 520037
• Marshfield Medical Center - Minocqua Hospital, Minocqua, WI, CCN 520212

Merit-based Incentive Payment System (MIPS)

Final score

86.59 of 100Reported as group

Quality

80.64

Promoting interoperability

100

Improvement activities

40

Cost

74.66

Merit-based Incentive Payment System (MIPS)

Final score

87.84 of 100Reported as group

Quality

86.21

Promoting interoperability

100

Improvement activities

40

Cost

73.25

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Osteopathy

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: him@marshfieldclinichealthsystem.cernerdirect.com

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.

• Beaver Dam Community Hospitals Inc

  • Clinic/Center
  • Beaver Dam, WI
  • NPI 1972188555
  Medicare reassignment NPD
• Flambeau Hospital Inc

  • Clinic/Center
  • Park Falls, WI
  • NPI 1194317966
  Medicare reassignment NPD
• Flambeau Hospital Inc

  • Critical Access Hospital
  • Park Falls, WI
  • NPI 1700963048
  Medicare reassignment NPD
• Lakeview Medical Center Inc of Rice Lake

  • Clinic/Center
  • Rice Lake, WI
  • NPI 1093201832
  Medicare reassignment NPD
• Marshfield Clinic Inc

  • Clinic/Center
  • Marshfield, WI
  • NPI 1952347981
  Medicare reassignment NPD
• MCHS Hospitals Inc

  • Clinic/Center
  • Marshfield, WI
  • NPI 1093221434

  Internal Medicine

  Medicare reassignment NPD
• MCHS Hospitals Inc

  • Critical Access Hospital
  • Ladysmith, WI
  • NPI 1952890873
  Medicare reassignment NPD
• Memorial Hospital Inc

  • Critical Access Hospital
  • Neillsville, WI
  • NPI 1346239373
  Medicare reassignment NPD
• Beaver Dam Community Hospitals Inc

  • Pharmacy
  • Beaver Dam, WI
  • NPI 1295771780
  NPD
• MCHS Hospitals Inc

  • Durable Medical Equipment & Medical Supplies
  • Eau Claire, WI
  • NPI 1558230847
  NPD

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

• Lakeview Medical Center Inc of Rice Lake

  • Rural Acute Care Hospital
  • Rice Lake, WI
  • NPI 1154415024
  Care Compare affiliation
• MCHS Hospitals Inc

  • Rural Acute Care Hospital
  • Minocqua, WI
  • NPI 1376197665
  Care Compare affiliation
• MCHS Hospitals Inc

  • General Acute Care Hospital
  • Weston, WI
  • NPI 1902437650
  Care Compare affiliation
• MCHS Hospitals Inc

  • Rural Acute Care Hospital
  • Marshfield, WI
  • NPI 1942749387
  Care Compare affiliation

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

{
    "created_epoch": "1374105600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1750204800000",
    "number": "1316389372",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1000 N OAK AVE",
            "city": "MARSHFIELD",
            "state": "WI",
            "postal_code": "544495702",
            "telephone_number": "715-387-5511"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "3400 MINISTRY PKWY",
            "city": "WESTON",
            "state": "WI",
            "postal_code": "544765220",
            "telephone_number": "715-393-1220"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "2251 N Shore Dr",
            "address_purpose": "LOCATION",
            "city": "Rhinelander",
            "state": "WI",
            "postal_code": "545016710",
            "country_code": "US",
            "telephone_number": "715-361-4700",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "GRZESIK",
        "first_name": "GREGORY",
        "middle_name": "WAYNE",
        "name_prefix": "Dr.",
        "credential": "D.O.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2013-07-18",
        "last_updated": "2025-06-18",
        "certification_date": "2025-06-18",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "WI",
            "license": "65797-21",
            "primary": false
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "IL",
            "license": "125-062888",
            "primary": false
        },
        {
            "code": "208M00000X",
            "taxonomy_group": "",
            "desc": "Hospitalist",
            "state": "WI",
            "license": "65797",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [
        {
            "endpointType": "DIRECT",
            "endpointTypeDescription": "Direct Messaging Address",
            "endpoint": "him@marshfieldclinichealthsystem.cernerdirect.com",
            "affiliation": "N",
            "address_1": "3400 Ministry Pkwy",
            "city": "Weston",
            "state": "WI",
            "country_code": "US",
            "postal_code": "544765220",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "other_names": []
}

• Lisa Gouthro, APSW
• Robert Vincent Gouthro Jr., M.D.
• Dylan Michael Graff, PA-C
• Debra Anna Gray, PT
• Gregory Cowan LLC
• Holly Guigauri
• Tracey M Gusman, LPC, SAC,NCC
• Carina Lea Hafner, OT
• Eric R Hall
• James David Hall, M.D.

• Hospitalist Physician in Weston, WI
• Providers in Weston, WI by specialty
• Hospitalist Physician in Wisconsin

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jun 18, 2025; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.