There are three types of acknowledgment that you may need to process when using HIPAA transactions. The Functional Acknowledgment (997) transaction is used to report problems at the functional group or transaction set level. This is located in the Transactions/997. The Implementation Acknowledgment (999) is used to provide additional implementation specification validation reporting. This is located in the Transactions/999-A1. Both the 997 and 999 are provided with and without the X12 envelope segments. For problems with the interchange or functional group (ISA/GS), the TA1 segment is used. This is found at Segments/TA1.