A generalization of list-coloring, now known as DP-coloring, was recently introduced by Dvořák and Postle [3]. Essentially, DP-coloring assigns an arbitrary matching between lists of colors at adjacent vertices, as opposed to only matching identical colors as is done for list-coloring. Several results on list-coloring of planar graphs have since been extended to the setting of DP-coloring [5,6,7,8,10,16]. We note that list-coloring results do not always extend to DP-coloring results, as shown in [2]. Our main result in this paper is to prove that every planar graph without cycles of length {4, a, b, 9} for a, b ∈ {6, 7, 8} is DP-3-colorable, extending three existing results [9, 13, 14] on 3-choosability of planar graphs.Definition 1.1. Let G be a simple graph with n vertices and let L be a list assignment for G. For each v ∈ V (G), let L v = {v} × L(v). For each edge uv ∈ E(G), let M uv be a matching