Abstract: A decision support tool is a computerized system for advising individuals who are choosing from available medical insurance plans/options for themselves or their families. The menu of available options might include as few as two plans as determined by the individual's employer, or it might include scores of plans on a direct-to-carrier basis or through a public or private exchange. The option that is best for one person or family is not best for all. Optimization for an individual or family is a function of likely medical consumption, the detailed benefit designs of the available plans, the individual's contribution to premium, and any employer contribution to an HSA, HRA or FSA (if applicable). The decision-support tool ranks available options from best-fit to worst-fit, and it quantifies the relative values via one Value Score per product.