The development of CFTR targeted therapy for cystic fibrosis has generated interest in maximizing membrane residence of mutant forms of CFTR by manipulating interactions with scaffold proteins such as NHERF1. In this study, we explored whether C-terminal sequences in CFTR beyond the PDZ-binding motif influence its interaction with NHERF1. NHERF1 displayed minimal self-association in blot overlays (NHERF1, Kd = 1382 ± 61.1 nM) at concentrations well above physiologic levels, estimated at 240 nM from RNA-Seq and 260 nM by LC-MS/MS in sweat gland, a key site of CFTR function in vivo. However, NHERF1 oligomerized at considerably lower concentrations (10 nM) in the presence of the last 111 amino acids of CFTR (20 nM) in blot overlays and cross-linking assays and in co-immunoprecipitations using differently tagged versions of NHERF1. Deletion and alanine mutagenesis revealed that a six amino acid sequence1417EENKVR1422 and the terminal 1478TRL1480 (PDZ-binding motif) in the C-terminus were essential for the enhanced oligomerization of NHERF1. Full-length CFTR stably expressed in MDCK epithelial cells fostered NHERF1 oligomerization that was substantially reduced (~5 fold) upon alanine substitution of EEN, KVR or EENKVR residues or deletion of the TRL motif. Confocal fluorescent microscopy revealed that the EENKVR and TRL sequences contribute to preferential localization of CFTR to the apical membrane. Together, these results indicate that C-terminal sequences mediate enhanced NHERF1 interaction and facilitate the localization of CFTR; a property that could be manipulated to stabilize mutant forms of CFTR at the apical surface to maximize the effect of CFTR-targeted therapeutics.