The Verification and Validation (V&V) program element of the ASC Program addresses concerns with the credibility and capability of computational simulations for the nuclear weapon stockpile. Verification activities deal with issues of software reliability and accuracy of numerical solutions to partial differential equations that describe physical processes. Validation activities deal with assessment of computational model accuracy by comparisons with experiment measurements throughout a hierarchy of physics complexity. Uncertainty quantification activities deal with procedures for representing all contributors to system uncertainty and show how these uncertainties contribute to predictions of system response for quantities of interest. All these activities contribute to predictive capability for the application of interest. Quantification of these activities must be provided to the decision makers so that computational simulations can improve design, performance assessment, and safety of high-consequence systems.