Verification, Model Checking, and Abstract InterpretationThis book constitutes the proceedings of the 21st International Conference on Verification, Model Checking, and Abstract Interpretation, VMCAI 2020. The 21 papers presented in this volume were carefully reviewed from 44 submissions. VMCAI provides a forum for researchers from the communities of verification, model checking, and abstract Interpretation, facilitating interaction, cross fertilization, and advancement of hybrid methods that combine these