Wiki Xu verses xs modifiers/ spinal coding

[ALB6284]

I'am aware of the modifier xs-separate structure and
xu-unusual non-overlapping service. As coding spinal surgery it confusing with additional vertrbra such as l1, l2, l3 etc. Should it be coded xu or xs. Its the same structure but a difeerient level.thanks for your replies

 

[BenCrocker]

XU is the more accurate in this case, UNLESS the CPT code has say an "Each additional level" code indented under it.