EDI 999
X12 implementation acknowledgment transaction set, mandated under HIPAA 5010.
Definition
Introduced with version 005010, the 999 replaces the 997 in the HIPAA scope. It reuses AK1/AK2 but adds IK3/IK4 (guide-level segment/element errors), IK5 (transaction verdict) and AK9 (group verdict), enabling it to flag implementation-guide deviations that the 997 cannot.
Origin
Defined as transaction set 999 in ASC X12 version 005010, with the matching HIPAA guide being TR3 005010X231, maintained by X12.
Example in context
ST*999*0001*005010X231A1~AK1*HC*17*005010X222A1~IK5*A~AK9*A*1*1*1~SE*5*0001~