Clinical and Laboratory Standards Institute document EP25-A--Evaluation of Stability of In Vitro Diagnostic Reagents; Approved Guideline provides guidance and regression-based procedures for establishing stability-related claims of in vitro diagnostic (IVD) reagents such as reagent kits, calibrators, control products, and sample diluents. This guideline was written primarily for manufacturers and regulatory agencies, but will also be of interest to clinical laboratories. It provides information on the design, implementation, data analysis, and documentation needs for studies to establish and verify shelf life and in-use life of IVD reagents. Additional topics address assessment of product transport conditions on stability and accelerated stability testing.