On December 8, 2017, U.S. Customs and Border Protection (CBP) announced in a Federal Register Notice (FRN), that as of January 6, 2018, ACE will be the sole CBP-authorized EDI system for generating, transmitting, and updating daily and monthly statements, and the Automated Commercial System (ACS) will no longer be a CBP-authorized EDI system for such purpose. The date previously set was December 9, 2017. Reconciliation (Type 09) entries will be transitioned at a later date.
The Federal Register Notice can be read here: