There is no direct interdependency requiring Loop 2300 Segment REF – Referral Number and Loop 2310A Segment NM1 Referring Provider if the other is present.

Loop 2300 Segment, REF – Referral Number is “Required when a referral number is assigned by the payer or Utilization Management Organization (UMO) AND a referral is involved.” Loop 2310A Segment NM1 - Referring Provider is “Required when this claim involves a referral.”

From a practical business perspective a referral is made by a referring provider and thus Loop 2310A Segment NM1 - Referring Provider is required because a referral is involved. In situations where a referral number is assigned by the payer or Utilization Management Organization (UMO) AND a referral is involved, then Loop 2300 Segment, REF – Referral Number is also required.

The usage of the two segments is dictated by the situational usage rule of each segment independent of the other. It is not correct from a TR3 usage perspective that one of the segments is required or not required by the presence or absence of the other.