NPIMap

Individual provider Active NPI

Grant August Wintheiser, MD

  • Medical Oncology Physician
  • Rochester, MN
National Provider Identifier
1043770092
Registry record updated Jul 20, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Medical Oncology PhysicianTaxonomy code 207RX0202X
License
67278 Issued in MN
Practice address
200 1St St SW
Rochester, MN 55905-0001
Phone
(507) 284-2511
NPI assigned
Mar 24, 2019
Sex
Male
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Jul 20, 2026

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

Specialties & licenses 3

Specialty (taxonomy)CodeLicenseStatePrimary
Internal Medicine Physician 207R00000X 67278 MN
Medical Oncology Physician 207RX0202X 67278 MN Primary
Hematology & Oncology Physician 207RH0003X 67278 MN

Addresses

Primary practice location

200 1St St SW
Rochester, MN 55905-0001

Mailing address

2925 Chicago Ave
Minneapolis, MN 55407-1321
Phone (612) 262-9000

Other practice location 1

11850 Blackfoot St NW Ste 300
Coon Rapids, MN 55433-2772
Phone (763) 236-0808

Electronic endpoints 2

TypeEndpointUseAffiliation
Direct Messaging Address gwintheiser731516@excellian.direct.allina.com Direct
Direct Messaging Address gwintheiser450433@ehrdirect.mayoclinicmsg.org

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in MN
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
I20200810002278 MN Practitioner - Hematology/OncologyPractitioner - Internal Medicine 2860726791 Reassigns benefits to 4 organizations

Care Compare profile

Medicare Care Compare
Specialty
Hematology/OncologyAlso: Internal Medicine
Education
Creighton University School of Medicine, 2019
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Telehealth
Offers telehealth services
Group practices
Allina Health SystemGroup PAC ID 4587573613, shared by 89 NPIs, 3,844 clinicians

Practice addresses (Care Compare)

225 Smith Ave N
Suite 200
Saint Paul, MN 55102-2697
Phone (651) 241-5111

701 Dellwood St S
Cambridge, MN 55008-1920
Phone (763) 688-8700

Hospital & facility affiliations

  • Mercy Hospital Hospital, Coon Rapids, MN, CCN 240115
  • Abbott Northwestern Hospital Hospital, Minneapolis, MN, CCN 240057
  • Cambridge Medical Center Hospital, Cambridge, MN, CCN 240020
  • Buffalo Hospital Hospital, Buffalo, MN, CCN 240076
  • Mayo Clinic Hospital Rochester Hospital, Rochester, MN, CCN 240010

National Provider Directory

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

State licenses

LicenseStateTypeSpecialty
30093MNMDClinical Social Worker

Practice roles

OrganizationSpecialtyStatusNew patients
Mayo Clinic CurrentSince Jul 1, 2020 Accepting new patients
Mayo Clinic Health System-Southeast Minnesota Region CurrentSince Apr 28, 2024 Accepting new patients
Mayo Clinic CurrentSince Jul 1, 2020 Accepting new patients
Allina Health System CurrentSince Jun 30, 2025 Accepting new patients
Allina Health System Current Accepting new patients
Mayo Clinic Health System-Southeast Minnesota Region CurrentSince Apr 28, 2024 Accepting new patients
Mayo Clinic Current Accepting new patients
Allina Health System CurrentSince Jun 30, 2025 Accepting new patients
Allina Health System Current Accepting new patients
Allina Health System CurrentSince Jun 30, 2025 Accepting new patients
Allina Health System Past Accepting new patients
Floyd County Memorial Hospital Commission Past Accepting new patients

Locations

404 W Fountain St
Albert Lea, MN 56007
Phone (507) 377-6285

440 Elm St E
Annandale, MN 55302
Phone (320) 682-5225

1000 1st Dr NW
Austin, MN 55912
Phone (507) 433-7351

701 Dellwood St S
Cambridge, MN 55008
Phone (763) 689-7700

11850 Blackfoot St NW
Ste 290
Coon Rapids, MN 55433
Phone (763) 236-0808

11850 Blackfoot St NW
Ste 300
Minneapolis, MN 55433
Phone (763) 236-0808

2925 Chicago Ave
Minneapolis, MN 55407
Phone (612) 262-4813

2925 Chicago Ave
#10957
Minneapolis, MN 55407
Phone (612) 262-8640

2215 Park Ave
Minneapolis, MN 55404
Phone (612) 775-8800

200 1st St SW
Rochester, MN 55905
Phone (507) 266-4850

225 Smith Ave N
Ste 200
Saint Paul, MN 55102
Phone (651) 241-5111

Interoperability endpoints

  • Direct secure messaging: gwintheiser731516@excellian.direct.allina.com

Organizations & group practices 12

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 37

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

View all 37

NPI Registry JSON

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

{
    "created_epoch": "1553385600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1784505600000",
    "number": "1043770092",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "2925 CHICAGO AVE",
            "city": "MINNEAPOLIS",
            "state": "MN",
            "postal_code": "554071321",
            "telephone_number": "612-262-9000"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "200 1ST ST SW",
            "city": "ROCHESTER",
            "state": "MN",
            "postal_code": "559050001",
            "telephone_number": "507-284-2511"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "11850 Blackfoot St NW Ste 300",
            "address_purpose": "LOCATION",
            "city": "Coon Rapids",
            "state": "MN",
            "postal_code": "554332772",
            "country_code": "US",
            "telephone_number": "763-236-0808",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "WINTHEISER",
        "first_name": "GRANT",
        "middle_name": "AUGUST",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2019-03-24",
        "last_updated": "2026-07-20",
        "certification_date": "2026-07-20",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "MN",
            "license": "67278",
            "primary": false
        },
        {
            "code": "207RX0202X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Medical Oncology",
            "state": "MN",
            "license": "67278",
            "primary": true
        },
        {
            "code": "207RH0003X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Hematology & Oncology",
            "state": "MN",
            "license": "67278",
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [
        {
            "endpointType": "DIRECT",
            "endpointTypeDescription": "Direct Messaging Address",
            "endpoint": "gwintheiser731516@excellian.direct.allina.com",
            "affiliation": "N",
            "use": "DIRECT",
            "useDescription": "Direct",
            "contentType": "OTHER",
            "contentTypeDescription": "Other",
            "contentOtherDescription": "CDA/PDF/TXT",
            "address_1": "11850 Blackfoot St NW Ste 300",
            "city": "Coon Rapids",
            "state": "MN",
            "country_code": "US",
            "postal_code": "554332772",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "endpointType": "DIRECT",
            "endpointTypeDescription": "Direct Messaging Address",
            "endpoint": "gwintheiser450433@ehrdirect.mayoclinicmsg.org",
            "affiliation": "N",
            "address_1": "200 1st St SW",
            "city": "Rochester",
            "state": "MN",
            "country_code": "US",
            "postal_code": "559050001",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "other_names": []
}

Other providers in Rochester, MN

Sources for this page

Verify at the official NPI Registry.