From US Customs’ September 2016 ACE Monthly Trade Update:
CBP continues to work with the PGAs to complete their integration in ACE. Below is a table listing all the agencies that have entry and entry summary requirements, their methods used to receive data in ACE via PGA Message Set or Document Image System (DIS), pilot availability and the commodities being piloted.
For additional information on PGA integration and to review the interim policy guidance on the reporting of PGA data, please visit the PGA Integration and ACE PGA Forms pages of CBP.gov/ACE.