Is it a violation for an information source (payer) to send a single 277 claim acknowledgment as a response to multiple separate 837 transactions (separate ST/SE envelopes)?
RFI #1991 and RFI #2145 seem somewhat related but do not directly address this question.
A payer is batching up claim acknowledgments and sending only a single 277CA transaction per claim submitter per day, regardless of how many 837 transactions they submitted that day.
Yes, it would be a violation of the TR3 to send a single 277CA (ST-SE) transaction in response to multiple 837 (ST-SE) transactions. According to the TR3 note at Loop 2200B, the TRN segment must contain the value submitted in the BHT03 from the 837. Therefore, the 277CA must be in response to the 837 claim transaction set. A transaction set is defined as ST segment through SE segment. Note, there can be multiple 277CA transactions batched within a single Interchange/Functional Group (ISA.GS/GE.IEA) within a single file transmission.