Frederick Richard Stack, MD

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

MD-46368 Issued in IA

Practice address

801 5TH St
Sioux City, IA 51101-1326

Phone

(712) 279-2010

Fax

(712) 279-2034

NPI assigned

Sep 21, 2005

Sex

Male

Sole proprietor

Yes

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

Specialties & licenses 3

Addresses

Other identifiers 3

Medicare fee-for-service enrollment

Enrolled in AZ, NM, MT, ME4 enrollments

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Enrollment records 4

Specialty

Internal Medicine

Education

University of Nebraska College of Medicine, 1991

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Benefis Hospitals IncGroup PAC ID 1153235296, 390 clinicians

Banner-University Medical GroupGroup PAC ID 7719899871, 1,066 clinicians

Pines Health ServicesGroup PAC ID 0749275113, 58 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Benefis Hospitals Inc Hospital, Great Falls, MT, CCN 270012
• Banner-University Medical Center South Campus Hospital, Tucson, AZ, CCN 030111
• Cary Medical Center Hospital, Caribou, ME, CCN 200031
• Logan Health - Shelby Hospital, Shelby, MT, CCN 271328
• Northern Rockies Medical Center Hospital, Cut Bank, MT, CCN 271337

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: fstack219058@direct.phs.org

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.

• Banner-University Medical Group

  • Multi-Specialty Clinic/Center
  • Phoenix, AZ
  • NPI 1508809427

  Internal Medicine

  Medicare reassignment Care Compare group NPD
• Benefis Hospitals Inc

  • Multi-Specialty Clinic/Center
  • Great Falls, MT
  • NPI 1780968974

  Specialist

  Medicare reassignment Care Compare group NPD
• Pines Health Services

  • Internal Medicine Physician
  • Caribou, ME
  • NPI 1942277819
  Medicare reassignment Care Compare group NPD
• City of Hope Medical Group of Arizona LLC

  • Medical Oncology Physician
  • Goodyear, AZ
  • NPI 1609026806

  Internal Medicine

  Medicare reassignment NPD
• Comprehensive Hospitalist Services of Arizona LLC

  • Hospitalist Physician
  • Mesa, AZ
  • NPI 1689909780
  Medicare reassignment NPD
• Eastern Maine Medical Center

  • General Acute Care Hospital
  • Bangor, ME
  • NPI 1790789147
  Medicare reassignment NPD
• Hospital Medicine Services of Maine LLC

  • Hospitalist Physician
  • Ellsworth, ME
  • NPI 1538638432
  Medicare reassignment NPD
• Hospitalist Medicine Physicians of Texas, PLLC

  • Internal Medicine Physician
  • Humble, TX
  • NPI 1629307095

  NM

  Medicare reassignment NPD
• Maine Medical Services LLC

  • Hospitalist Physician
  • Ellsworth, ME
  • NPI 1053878371

  Internal Medicine

  Medicare reassignment NPD
• Page Hospital

  • Critical Access Hospital
  • Page, AZ
  • NPI 1578515789
  Medicare reassignment NPD
• St Peter'S Health

  • General Acute Care Hospital
  • Helena, MT
  • NPI 1205025145
  Medicare reassignment NPD
• Banner-University Medical Group

  • Nutrition Education Nutritionist
  • Tucson, AZ
  • NPI 1639842677
  NPD

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

• Banner - University Medical Center South Campus LLC

  • General Acute Care Hospital
  • Tucson, AZ
  • NPI 1558759498
  Care Compare affiliation
• Banner - University Medical Center South Campus LLC

  • Nutrition Education Nutritionist
  • Tucson, AZ
  • NPI 1922660182

  Hospital

  Care Compare affiliation
• Benefis Hospitals Inc

  • Multi-Specialty Clinic/Center
  • Great Falls, MT
  • NPI 1780968974

  Hospital

  Care Compare affiliation
• Benefis Hospitals, Inc.

  • Air Ambulance
  • Great Falls, MT
  • NPI 1114934023

  Hospital

  Care Compare affiliation
• Benefis Hospitals, Inc.

  • General Acute Care Hospital
  • Great Falls, MT
  • NPI 1881650737
  Care Compare affiliation
• City of Caribou

  • General Acute Care Hospital
  • Caribou, ME
  • NPI 1780615492
  Care Compare affiliation
• Logan Health - Shelby

  • Critical Access Hospital
  • Shelby, MT
  • NPI 1497742415
  Care Compare affiliation
• Northern Rockies Medical Center, Inc.

  • Critical Access Hospital
  • Cut Bank, MT
  • NPI 1831143080
  Care Compare affiliation

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

{
    "created_epoch": "1127260800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1769558400000",
    "number": "1548256977",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "6909 EAST RAY ROAD #15-114",
            "city": "CHANDLER",
            "state": "AZ",
            "postal_code": "85226",
            "telephone_number": "520-421-1122",
            "fax_number": "520-421-0751"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "801 5TH ST",
            "city": "SIOUX CITY",
            "state": "IA",
            "postal_code": "511011326",
            "telephone_number": "712-279-2010",
            "fax_number": "712-279-2034"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "1821 N Trekell Rd",
            "address_2": "Suite 6",
            "address_purpose": "LOCATION",
            "city": "Casa Grande",
            "state": "AZ",
            "postal_code": "852221705",
            "country_code": "US",
            "telephone_number": "520-421-1122",
            "fax_number": "520-421-0751",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "1 Medical Center Dr",
            "address_purpose": "LOCATION",
            "city": "Biddeford",
            "state": "ME",
            "postal_code": "040059422",
            "country_code": "US",
            "telephone_number": "207-283-7937",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "1101 26th St S",
            "address_purpose": "LOCATION",
            "city": "Great Falls",
            "state": "MT",
            "postal_code": "594055161",
            "country_code": "US",
            "telephone_number": "406-455-4694",
            "fax_number": "406-731-8318",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "STACK",
        "first_name": "FREDERICK",
        "middle_name": "RICHARD",
        "name_prefix": "Dr.",
        "credential": "MD",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2005-09-21",
        "last_updated": "2026-01-28",
        "certification_date": "2026-01-28",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "MT",
            "license": "91977",
            "primary": false
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "IA",
            "license": "MD-46368",
            "primary": true
        },
        {
            "code": "174400000X",
            "taxonomy_group": "",
            "desc": "Specialist",
            "state": "AZ",
            "license": "24459",
            "primary": false
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "436693002",
            "state": "AZ"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "BLUE CROSS BLUEE SHIELD",
            "identifier": "AZ0866740",
            "state": "AZ"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "MEDICARE RAILROAD",
            "identifier": "110208816",
            "state": "AZ"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• St Luke'S Health Resources
• St Lukes Health Resources
• St Lukes Health Resources
• St. Luke'S Health Resources
• Annie L Stachowitz, PH.D.
• Chad Allen Stadsvold, DO
• Jane Stanley, PT
• Startingpoints Family Therapy
• Angela Lee Stearns, OTD, MS, OTR/L, BCG
• Brianna Steffe, CADC

• Internal Medicine Physician in Sioux City, IA
• Providers in Sioux City, IA by specialty
• Internal Medicine Physician in Iowa

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jan 28, 2026; 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.