A system provides dynamic interference avoidance in integrated multi-radio access technology (RAT) heterogeneous networks (Het-Nets). A multi-mode user equipment accesses mobile communications services using RATs. An integrated node provides a primary cell and at least one secondary cell to the multi-mode user equipment. Initial radio access technologies (RATs) are assigned to the multi-mode user equipment from among a plurality of RATs for use by the multi-mode user equipment. Quality metrics are collected across the plurality of RATs. RAT assignments are re-evaluated based on the collected quality metrics. To provide dynamic interference mitigation in multi-RAT Het-Nets, RAT assignments are periodically repartitioned from among the plurality of RATs for use by the multi-mode user equipment based on the re-evaluation of RAT assignments using the collected quality metrics.