Katherine Onnen Ryken, M.D.

Primary specialty

Obstetrics & Gynecology PhysicianTaxonomy code 207V00000X

License

322155 Issued in NY

Practice address

565 Abbott Rd
Buffalo, NY 14220-2039

Phone

(206) 520-5000

NPI assigned

Mar 21, 2017

Sex

Female

Sole proprietor

No

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

Specialties & licenses 5

Addresses

Other identifiers 1

Medicare fee-for-service enrollment

Enrolled in NY, ME2 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 2

Specialty

Obstetrics/Gynecology

Education

Other, 2017

Medicare assignment

May accept Medicare assignment

Practice addresses (Care Compare)

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

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.

• Kenmore Mercy Hospital

  • General Acute Care Hospital
  • Kenmore, NY
  • NPI 1770598104
  Medicare reassignment NPD
• Mercy Hospital of Buffalo

  • General Acute Care Hospital
  • Buffalo, NY
  • NPI 1164464921
  Medicare reassignment NPD
• Mount St. Mary's Hospital of Niagara Falls

  dba Mount St. Mary's Hospital and Health Center

  • General Acute Care Hospital
  • Lewiston, NY
  • NPI 1043394745
  Medicare reassignment NPD
• Sisters of Charity Hospital of Buffalo New York

  • General Acute Care Hospital
  • Buffalo, NY
  • NPI 1790727543
  Medicare reassignment NPD
• Bridgton Hospital

  • Critical Access Hospital
  • Bridgton, ME
  • NPI 1154370153
  Medicare reassignment
• Central Maine Medical Center

  • General Acute Care Hospital
  • Lewiston, ME
  • NPI 1689653487
  Medicare reassignment
• Rumford Hospital

  • Critical Access Hospital
  • Rumford, ME
  • NPI 1205991122
  Medicare reassignment
• Eastern Great Lakes Pathology PC

  • Anatomic Pathology & Clinical Pathology Physician
  • Buffalo, NY
  • NPI 1467481564
  NPD
• Kenmore Mercy Hospital

  dba Kenmore Mercy Professional Services

  • Pulmonary Disease Physician
  • Kenmore, NY
  • NPI 1659909752
  NPD
• Mercy Hospital of Buffalo

  dba Mercy Hospital Professional Services

  • General Acute Care Hospital
  • Buffalo, NY
  • NPI 1851929954
  NPD
• Mount St. Mary's Hospital of Niagara Falls

  dba Mount St. Mary's Professional Services

  • General Acute Care Hospital
  • Lewiston, NY
  • NPI 1184252751
  NPD
• Sisters of Charity Hospital of Buffalo New York

  • General Acute Care Hospital
  • Cheektowaga, NY
  • NPI 1043455199
  NPD

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

{
    "created_epoch": "1490054400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1774569600000",
    "number": "1487185633",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "565 ABBOTT RD",
            "city": "BUFFALO",
            "state": "NY",
            "postal_code": "142202039"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "565 ABBOTT RD",
            "city": "BUFFALO",
            "state": "NY",
            "postal_code": "142202039",
            "telephone_number": "206-520-5000"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "RYKEN",
        "first_name": "KATHERINE",
        "middle_name": "ONNEN",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "F",
        "enumeration_date": "2017-03-21",
        "last_updated": "2026-03-27",
        "certification_date": "2026-03-27",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "AK",
            "license": "241504",
            "primary": false
        },
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "WA",
            "license": "MD61136628",
            "primary": false
        },
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "NY",
            "license": "322155",
            "primary": true
        },
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "ME",
            "license": "MD29498",
            "primary": false
        },
        {
            "code": "207V00000X",
            "taxonomy_group": "",
            "desc": "Obstetrics & Gynecology",
            "state": "CO",
            "license": "0076454",
            "primary": false
        }
    ],
    "identifiers": [
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "1487185633",
            "state": "WA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Alexander Brian Rybarczyk, MSW
• Emily M Rybczynski, OTR/L
• Mia Rydelek
• Susan Marie Rydzyk, MS RPA-C
• Sarah Elizabeth Rydzynski
• Mary A Rykert-Wolf, MD
• Joseph A. Ryndak, PHARMD
• Chelsea Renee Ryniec
• Daniel Ryszka
• S K Gulati MD PC

• Obstetrics & Gynecology Physician in Buffalo, NY
• Providers in Buffalo, NY by specialty
• Obstetrics & Gynecology Physician in New York

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Mar 27, 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.