Temporal interference stimulation (TIS) is a non-invasive brain stimulation technique that exploits frequency-shifted kHz fields to modulate oscillatory neural activity. While human studies suggest TIS efficacy in target-ing relatively deep brain structures, recent computational modeling and animal studies indicate potential off-target stimulations via standard TIS protocols. Here, we computationally optimized TIS targeting for the medial prefrontal cortex (mPFC) in mice. Combining in vivo electrophysiological recordings, intracellular cal-cium dynamics with fiber photometry, and functional MRI, we confirmed TIS-induced amplitude modulation, neuronal entrainment, and hemodynamic responses in the mPFC, while also identifying off-target modula-tions. To mitigate off-target effects, we introduced a configuration with three electrode pairs, one of which is actively phase-shifted by 180 degrees. This canceling field enhanced TIS focality, thereby reducing off-target ef-fects without compromising TIS efficacy in the target area. This work effectively addresses one of TIS's most critical shortcomings and opens new avenues for research and clinical applications. A record of this paper's transparent peer review process is included in the supplemental information.