We report infrared studies of the insulator-to-metal transition (IMT) in GaAs doped with either magnetic (Mn) or non-magnetic acceptors (Be). We observe a resonance with a natural assignment to impurity states in the insulating regime of Ga1−xMnxAs, which persists across the IMT to the highest doping (16%). Beyond the IMT boundary, behavior combining insulating and metallic trends also persists to the highest Mn doping. Be doped samples however, display conventional metallicity just above the critical IMT concentration, with features indicative of transport within the host valence band.The insulator-to-metal transition (IMT) becomes exceptionally complex when magnetism is involved, as proven in materials such as mixed-valence manganites, rare-earth chalcogenides, and Mn-doped III-V compounds [1,2]. In all these systems, the electronic and magnetic properties are typically interconnected, creating an entising challenge to understand how magnetism affects the IMT physics. A promising route to isolate differences attributable to the presence of magnetism on the IMT physics is to investigate either magnetic or non-magnetic dopants in the same host. p-doped GaAs is well suited for the task since metallicity in this material can be initiated by non-magnetic (Zn, Be, C) and magnetic (Mn) acceptors. Infrared (IR) experiments reported here for Ga 1−x Be x As and Ga 1−x Mn x As monitor the charge dynamics and electronic structure in the course of the IMT. Our results establish that the onset arXiv:1109.0310v1 [cond-mat.mtrl-sci] 1 Sep 2011