NPIMap

Individual provider Active NPI

Ivar Leslie Frithsen, MD

  • Family Medicine Physician
  • Keene, NH
National Provider Identifier
1891803755
Registry record updated Sep 30, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Family Medicine PhysicianTaxonomy code 207Q00000X
License
25940 Issued in SC
Practice address
580 Court St
Keene, NH 03431-1718
Phone
(603) 354-5454
NPI assigned
Aug 29, 2006
Last updated
Sep 30, 2026By the provider in NPPES
Sex
Male
Sole proprietor
No

NPPES NPI Registry

Updated by the provider on Sep 30, 2026

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

Specialties & licenses 2

Specialty (taxonomy)CodeLicenseStatePrimary
Family Medicine Physician 207Q00000X 15569 NH
Family Medicine Physician 207Q00000X 25940 SC Primary

Addresses

Primary practice location

580 Court St
Keene, NH 03431-1718

Mailing address

580 Court St
Keene, NH 03431-1718
Phone (603) 354-5454

Other practice location 1

181 Corliss Ln
Colebrook, NH 03576-3207
Phone (603) 237-4971

Other practice location 2

173 Middle St
Lancaster, NH 03584-3508
Phone (603) 788-2521

Other practice location 3

59 Page Hill Rd
Berlin, NH 03570-3531
Phone (603) 788-5764

Other identifiers 3

IdentifierTypeStateIssuer
32001211MedicaidNH
3075101MedicaidNH
259400MedicaidSC

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in NH, VT2 enrollments
Eligible to order & refer
  • Part B services
  • Medical equipment
  • Home health
  • Power mobility devices
  • Hospice
Green means eligible to order or refer.

Enrollment records 2

Enrollment IDStateProvider typePAC IDDetails
I20120405000070 NH Practitioner - Family Practice 6901834779 Reassigns benefits to 4 organizations
I20240930002320 VT Practitioner - Family Practice 6901834779 Reassigns benefits to 4 organizations

Care Compare profile

Medicare Care Compare
Specialty
Family Practice
Education
Other, 2002
Medicare assignment
Accepts the Medicare-approved amount as payment in full
Group practices
Northeastern Vermont Regional Hospital IncGroup PAC ID 3678481405, shared by 15 NPIs, 104 clinicians
Brattleboro Memorial HospitalGroup PAC ID 9335112929, 70 clinicians
Littleton Hospital AssociationGroup PAC ID 6901796556, 111 clinicians

Practice addresses (Care Compare)

1315 Hospital Dr
Saint Johnsbury, VT 05819-9210
Phone (802) 748-8141

17 Belmont Ave
Brattleboro, VT 05301-7601
Phone (802) 257-0341

600 Saint Johnsbury Rd
Littleton, NH 03561-3442
Phone (603) 444-9000

Hospital & facility affiliations

Merit-based Incentive Payment System (MIPS)

Final score
93.17 of 100Reported as group
Quality
84.29
Promoting interoperability
96
Improvement activities
40

National Provider Directory

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

Practice roles

OrganizationSpecialtyStatusNew patients
Northeastern Vermont Regional Hospital, Inc Current Accepting new patients
Springfield Hospital CurrentSince Aug 14, 2024 Accepting new patients
Littleton Hospital Association CurrentSince Apr 20, 2025 Accepting new patients
Littleton Hospital Association CurrentSince Apr 20, 2025 Accepting new patients
Northeastern Vermont Regional Hospital, Inc CurrentSince Feb 18, 2025 Accepting new patients
Northeastern Vermont Regional Hospital, Inc CurrentSince Jan 27, 2026 Accepting new patients
Brattleboro Memorial Hospital Family Medicine CurrentSince Apr 19, 2025 Accepting new patients
Northeastern Vermont Regional Hospital, Inc Current Accepting new patients
Northeastern Vermont Regional Hospital, Inc Current Accepting new patients
Northeastern Vermont Regional Hospital Inc. CurrentSince Feb 18, 2025 Accepting new patients
Northeastern Vermont Regional Hospital Inc Current Accepting new patients
Springfield Hospital .Inc CurrentSince Aug 14, 2024 Accepting new patients

Locations

580 Saint Johnsbury Rd
Littleton, NH 03561
Phone (603) 444-0385

600 Saint Johnsbury Rd
Littleton, NH 03561
Phone (603) 444-9000

17 Belmont Ave
Brattleboro, VT 05301
Phone (802) 257-8360

25 Ridgewood Rd
Springfield, VT 05156
Phone (780) 281-9593

1315 Hospital Dr
St Johnsbury, VT 05819
Phone (802) 748-3638

Interoperability endpoints

  • FHIR API: https://fhir-myrecord.cerner.com/r4/d9dc001d-1bc5-42f9-bd4d-eb79208fd32a/
  • Direct secure messaging: vrhifrith@yourcarecommunity.org

Organizations & group practices 14

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

View all 14

Hospital & facility affiliations 7

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

NPI Registry JSON

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

{
    "created_epoch": "1156809600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1790726400000",
    "number": "1891803755",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "580 COURT ST",
            "city": "KEENE",
            "state": "NH",
            "postal_code": "034311718",
            "telephone_number": "603-354-5454"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "580 COURT ST",
            "city": "KEENE",
            "state": "NH",
            "postal_code": "034311718",
            "telephone_number": "603-354-5454"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "181 Corliss Ln",
            "address_purpose": "LOCATION",
            "city": "Colebrook",
            "state": "NH",
            "postal_code": "035763207",
            "country_code": "US",
            "telephone_number": "603-237-4971",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "173 Middle St",
            "address_purpose": "LOCATION",
            "city": "Lancaster",
            "state": "NH",
            "postal_code": "035843508",
            "country_code": "US",
            "telephone_number": "603-788-2521",
            "country_name": "United States",
            "address_type": "DOM"
        },
        {
            "address_1": "59 Page Hill Rd",
            "address_purpose": "LOCATION",
            "city": "Berlin",
            "state": "NH",
            "postal_code": "035703531",
            "country_code": "US",
            "telephone_number": "603-788-5764",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "FRITHSEN",
        "first_name": "IVAR",
        "middle_name": "LESLIE",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-08-29",
        "last_updated": "2026-09-30",
        "certification_date": "2026-09-30",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207Q00000X",
            "taxonomy_group": "",
            "desc": "Family Medicine",
            "state": "NH",
            "license": "15569",
            "primary": false
        },
        {
            "code": "207Q00000X",
            "taxonomy_group": "",
            "desc": "Family Medicine",
            "state": "SC",
            "license": "25940",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "32001211",
            "state": "NH"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "3075101",
            "state": "NH"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "259400",
            "state": "SC"
        }
    ],
    "endpoints": [],
    "other_names": []
}

Other providers in Keene, NH

Sources for this page

Verify at the official NPI Registry.