A pharmacy benefits plan is designed such that covered scripts are placed into Groups and allowances are provided for the purchase of scripts within each Group. Each Group comprises scripts for pharmaceuticals that provide medical benefits within a given time frame. A first Major Group is assigned to scripts for drugs that are prescribed for conditions that would otherwise result in further medical treatment and expense if said drugs were not taken by an insured. A second Major Group is assigned to scripts for drugs that are prescribed for conditions that would not normally result in subsequent medical costs if the drugs were not taken. Relatively high allowances are provided for scripts in said first Major Group such that the out-of-pocket costs of a given script will not be a barrier to said insured obtaining and taking said scripts. Relatively low allowances are provided for scripts in said second Major Group such that an insured will be further motivated to ask their doctor about low cost alternative drugs for a given treatment.