In this talk, I will discuss the decay of solutions to the wave equation on slowly-rotating extremal Kerr-Newman black holes. The behavior of waves on extremal spherically symmetric black holes and axisymmetric waves on rotational extremal black holes has seen remarkable recent developments. I will discuss how these developments can be extended to the case of slowly-rotating extremal Kerr-Newman, highlighting the similarities between the structure of the wave operator at null infinity and the structure of the wave operator at the extremal horizon. This is joint work with Allen Fang and Jingbo Wan.