Are all the data elements included in the CORE-require Minimum Data Elements specified in the non-X12 method section of the CAQH CORE Attachments Claims Data Content Rules required if the information is not available to the provider?

Do the CORE-required Minimum Data Elements specified in the non-X12 method section of the CAQH CORE Attachments Claims Data Content Rules need to correspond to X12 data elements?

No. The data does not need to conform to X12 data element naming conventions and as such, do not need to correspond to those X12 data elements as it is not an X12 transaction.

If a provider does not send all data elements listed in the CAQH CORE Attachments Claims Data Content Rules to assist with reassociation, can the health plan request that the provider send the data elements listed in the rule?

No. The list of data elements is recommended to assist with reassociation. The data elements should only be sent, if available, to the provider at the time of submissions. The lists of data elements in the rules are not prohibitive or exhaustive.

How was the list of common reference data for reassociating an X12 275 and an X12 837 developed?