Caught in the dilemma of too few vocational rehabilitation slots to serve all interested consumers, agencies often have been accused of ''creaming''-offering vocational opportunities primarily to those with the greatest likelihood of employment success. Project WINS sought to implement a cost-effective method of enhancing vocational services to individuals with severe mental illness served by mental health agencies, through the addition of vocational specialists (and other supports) to case management teams. The major principles guiding implementation had relevance for the process by which clients should receive vocational intervention: 1) toward zero exclusion of individuals from vocational services; 2) client self-determination of vocational goals, desires, and needs for service; and 3) the choose/get/keep model, tailoring interventions to individual clients, whatever their stage of vocational development. Clients were referred to WINS primarily through case managers, although self-referrals were accepted. Predictive analyses (logistic regression and survival analysis) identified variables that differentiated clients who received services during the first 18 months of WINS operation from those who did not. Potential predictors came from four domains: demographic and background characteristics; descriptors of psychiatric status and community functioning; work history and expectations; and agency setting variables. Results indicated that systematic client selection occurred: some elements of selection reflected the intervention's guiding principles, while other selection factors reflected traditional labor market variables. Discussion includes application of findings to implementation of vocational interventions in mental health case management agencies.