Sorting nexin 9 (SNX9) is a membrane-binding scaffold protein that contributes to viral uptake and inflammation and is associated with worse outcomes in several cancers. It is involved in endocytosis of epidermal growth factor receptors, β1-integrin and membrane type 1 matrix metalloprotease, and formation of mitochondrial-derived vesicles. The SNX9 Bin-Amphiphysin-Rvs (BAR)-Phox homology (PX) domains bind phosphoinositide lipids and the Src homology 3 (SH3) domain interacts with dynamin and Neural-Wiskott Aldrich syndrome protein (N-WASP) to stimulate Arp2/3 complex-mediated actin polymerization. Here we use biolayer interferometry, cell-free reconstitution, and superresolution microscopy to analyze the specificity and activities of SNX9 at membranes. We find that more SNX9 can bind liposomes containing phosphatidylinositol (4,5)-bisphosphate (PI(4,5)P