Abstract : This report presents a complete, detailed methodology for deriving quantitative estimates of program/system cost-risk. The procedures for completely algebraic and direct. They do not rely on Monte Carlo or Method of Moments techniques. Principle sources of uncertainty that contribute to cost- risk are identified for each of the four costing approaches treated in the methodology: Parametric Costing Approach; Engineering (Bottom-Up/Grass Roots) Costing Approach; Analogous (Scaling) Costing Approach; and Constant Multiplier Costing Approach.