{"filing":{"accession_number":"0001888524-26-016512","cik":"0001698685","ticker":null,"company_name":"BANK 2017-BNK4","form":"8-K","filing_date":"2026-09-02","report_date":"2026-09-01","primary_document":"wcm17bk4_8k-09012026.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/1698685/000188852426016512/wcm17bk4_8k-09012026.htm"},"events":[{"id":31200,"run_id":28620,"accession_number":"0001888524-26-016512","anchor_item_number":"6.02","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"summary":"This disclosure reports a change of servicer under Item 6.02, specifically the transfer of special servicing duties from Greystone Servicing Company LLC to C-IV Asset Management LLC effective September 1, 2026. The transaction involves approximately $20.7 billion in aggregate stated principal balance across 60 transactions and 1,928 first-lien mortgage loans. While the Item 6.02 category is dedicated to servicer/trustee changes, the event itself is operational in nature—a material business transition affecting the administration of a substantial mortgage securitization portfolio. The disclosure is material because it affects the operational continuity and management of significant assets underlying the securitization.","company_name":"BANK 2017-BNK4","ticker":null,"filing_date":"2026-09-02","form":"8-K","submitted_at":null,"items":[{"id":34020,"accession_number":"0001888524-26-016512","item_number":"6.02","item_title":"Change of Servicer or Trustee.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"This disclosure reports a change of servicer under Item 6.02, specifically the transfer of special servicing duties from Greystone Servicing Company LLC to C-IV Asset Management LLC effective September 1, 2026. The transaction involves approximately $20.7 billion in aggregate stated principal balance across 60 transactions and 1,928 first-lien mortgage loans. While the Item 6.02 category is dedicated to servicer/trustee changes, the event itself is operational in nature—a material business transition affecting the administration of a substantial mortgage securitization portfolio. The disclosure is material because it affects the operational continuity and management of significant assets underlying the securitization.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-02T13:09:43.452903+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":34020,"accession_number":"0001888524-26-016512","item_number":"6.02","item_title":"Change of Servicer or Trustee.","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"This disclosure reports a change of servicer under Item 6.02, specifically the transfer of special servicing duties from Greystone Servicing Company LLC to C-IV Asset Management LLC effective September 1, 2026. The transaction involves approximately $20.7 billion in aggregate stated principal balance across 60 transactions and 1,928 first-lien mortgage loans. While the Item 6.02 category is dedicated to servicer/trustee changes, the event itself is operational in nature—a material business transition affecting the administration of a substantial mortgage securitization portfolio. The disclosure is material because it affects the operational continuity and management of significant assets underlying the securitization.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-02T13:09:43.452903+00:00","company_name":"BANK 2017-BNK4","ticker":null,"filing_date":"2026-09-02"}]}