The cell division cycle 25 phosphatases CDC25A, B and C regulate cell cycle transitions by dephosphorylating residues in the conserved glycine-rich loop of cyclin-dependent protein kinases (CDKs) to activate CDK activity. Here, we present HDX-MS data to complement the cryogenic-electron microscopy (cryo-EM) structure of CDK2-cyclin A in complex with CDC25A, providing a detailed structural analysis of the overall complex architecture and key protein-protein interactions that underpin this 86 kDa complex. This work improves our understanding of the roles of CDC25 phosphatases in CDK regulation and may inform the development of CDC25-targeting anticancer strategies.