One specific payor is returning 277CA responses and 835 Remittance information in the same file. I was unsuccessful in locating in the front matter of the X12 Imp guide where it states if this is or is not allowed. I understand that it is possible to return multiple 835 files in the same file, but does this apply to different transaction types? Can you please clarify if payors are able to combine 277CA response files and 835 files in the same returned file?
See figure B.1 in appendix B of any of the 5010 guides. Multiple Functional Groups (GS/GE) are explicitly allowed within a single Interchange (ISA/IEA). Each Functional Group is identified in GS01 by a Functional Identifier Code which identifies the specific type of transaction within the Functional Group, as identified in section 1.2 of the related TR3 and the GS detail in Appendix C.
As long as the 835 transactions are within a GS/GE with GS01 equal to “HP”, and the 277CA transactions are within a separate GS/GE where GS01 is equal to “HN”, the ASC X12 structure explicitly supports sending 835s and 277CAs within the same Interchange.