An overview of Mexican subduction is presented; including young lithosphere, flat slab subduction, and current knowledge of the position of the subducting Cocos and Rivera plates. North of the Trans-Mexican Volcanic Belt (TMVB) those positions become unclear. Geochemical analysis suggests that there may be a slab tear causing mafic volcanism along the northern edge of the (TMVB). A torn slab would suggest that the properties of subduction (i.e. possibly the age of the lithosphere and rate of subduction) have changed since its initiation. Moreover, a stub slab is sufficient to maintain subduction.