As post-secondary institutions assume more responsibility for the language abilities of their graduates, more attention is being paid to post-admission language support to enhance student success. Previous research has indicated that a post-admission language diagnostic assessment procedure, when coupled with language support services, can be an effective model in helping students meet language expectations in post-secondary settings. This paper outlines the development and validation of a screening-diagnostic assessment procedure to recommend students to language support services in college diploma programs. Our key findings suggest that students who receive a recommendation through the procedure and subsequently attend language support (LS) classes have higher communication grades than those who do not attend, and that testing vocabulary can be an effective measure for screening language abilities. These results offer validity evidence for using this procedure while ongoing research is being conducted to validate its testing measures.