Katherine Lynn Klaassen, MD

Primary specialty

Geriatric Psychiatry PhysicianTaxonomy code 2084P0805X

License

18532 Issued in OK

Practice address

1011 Honor Heights Dr
Department of Veterans Affairs- Medical Center
Muskogee, OK 74401-1318

Phone

(918) 680-3699

Fax

(918) 680-3701

NPI assigned

Aug 9, 2006

Last updated

Sep 11, 2025By the provider in NPPES

Sex

Female

Sole proprietor

Yes

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

Specialties & licenses 2

Addresses

Medicare fee-for-service enrollment

Not listed in the public Medicare enrollment file

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Interoperability endpoints

• FHIR API: https://epicproxy.ardenthealth.com/fhir/UPC/api/FHIR/R4

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.

• Ahs Hillcrest Medical Center, LLC

  dba Hillcrest Medical Center

  • General Acute Care Hospital
  • Tulsa, OK
  • NPI 1629057229
  NPD (past)
• Ahs Oklahoma Physician Group LLC

  dba Utica Park Clinic

  • Family Medicine Physician
  • Tulsa, OK
  • NPI 1235182775
  NPD (past)

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

{
    "created_epoch": "1155081600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1757548800000",
    "number": "1114937034",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1011 HONOR HEIGHTS DR",
            "address_2": "DEPARTMENT OF VETERANS AFFAIRS- MEDICAL CENTER",
            "city": "MUSKOGEE",
            "state": "OK",
            "postal_code": "744011318",
            "telephone_number": "918-680-3699",
            "fax_number": "918-680-3701"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1011 HONOR HEIGHTS DR",
            "address_2": "DEPARTMENT OF VETERANS AFFAIRS- MEDICAL CENTER",
            "city": "MUSKOGEE",
            "state": "OK",
            "postal_code": "744011318",
            "telephone_number": "918-680-3699",
            "fax_number": "918-680-3701"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "KLAASSEN",
        "first_name": "KATHERINE",
        "middle_name": "LYNN",
        "credential": "MD",
        "sole_proprietor": "YES",
        "sex": "F",
        "enumeration_date": "2006-08-09",
        "last_updated": "2025-09-11",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "2084P0800X",
            "taxonomy_group": "",
            "desc": "Psychiatry & Neurology, Psychiatry",
            "state": "OK",
            "license": "18532",
            "primary": false
        },
        {
            "code": "2084P0805X",
            "taxonomy_group": "",
            "desc": "Psychiatry & Neurology, Geriatric Psychiatry",
            "state": "OK",
            "license": "18532",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Ruth Kirk
• Kirk's Drug, Inc.
• Clifford Ryan Kissling
• Lindsay Kizzia
• Phillip Lee Kizzia
• Sunnie Daise Klutts
• Bobbi A. Knack, MSW, LCSW
• KND Development 59, LLC (Specialty Hospitals Muskogee)
• Brittany E Knight
• Samantha Knight

• Geriatric Psychiatry Physician in Muskogee, OK
• Providers in Muskogee, OK by specialty
• Geriatric Psychiatry Physician in Oklahoma

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Sep 11, 2025; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.