Unlike traditional biologics, mRNAs are large and delicate molecules, which need to be protected by lipid nanoparticles (LNPs) before they reach target cells. Analytical characterization of mRNA therapeutics presents unique challenges that require new technologies and solutions. Liquid Chromatography (LC), and High-Resolution, Accurate-Mass (HRAM) Mass Spectrometers (MS) workflows can be used for robust characterization of mRNA drug product (DP) and drug substance (DS) critical quality attributes such as identity, capping efficiency, poly(A) tail length, and LNP composition.