This issue is explicitly addressed in Guide 005010X222A1. The 2300 CR1 segment Situational Rule reads in part “Required on all claims involving ambulance transport services.” The Situational Rule for the CR101 element reads in part, “Required when it is necessary to justify the medical necessity of the level of ambulance services”. If these conditions are met, then the 2300 CR1 segment and 2300 CR101 element are required.

Also as you state in your RFI description, “The CR1 segment in Loop ID-2300 applies to the entire claim unless overridden by a CR1 segment at the service line level in Loop ID-2400 with the same value in CR101”.

The Situational Rule of the 2400 loop CR1 segment reads in part as follows: “Required on ambulance transport services when the information applicable to any one of the segment's elements is different than the information reported in the CR1 at the claim level (Loop ID-2300).”

Therefore, if the information applicable to any one of the segment's elements is not different than the information reported in the CR1 at the claim level, the 2400 CR1 must not be sent. The value of the CR101, if sent at both levels must be ‘LB’ since that is the only allowed value. To meet the 2400 loop CR1 Situational Rule, information in another element must be different. If the 2400 loop CR1 segment is sent, per the TR3 note it overrides the information in the 2300 loop CR1.