In Research Article e6080664, Lulu Xue and co-workers present a ligand-mediated lipid reprogramming strategy that redirects liver-tropic ionizable lipids toward lung-selective mRNA delivery. Site-specific installation of small-molecule ligands onto the headgroup of the 2-t6b ionizable lipid enables precise organ retargeting while preserving the parent scaffold, resulting in markedly enhanced efficacy for lung-targeted mRNA delivery and genome editing applications.