This study had the objectives of developing a career coaching program for adolescents with intellectual disability and examining the effect of the program. For the goals, the study developed a career coaching program on the basis of ADDIE(Analysis, Design, Development, Implementation, Evaluation) modeling. In order to examine the effect of the developed program, this research selected 12 students with mild intellectual disability, or specifically, six from a special class of B school located in Busan and another six from such class of D school in the same city. And then, the study divided and randomly allocated the twelve participants into experiment and control groups each having 6 members. The developed program was applied to the participants over 7 sessions from Sep. 26th to Oct. 18th based on 2 sessions a week(100 minutes per session), and the study attempted to determine whether that program had a statistically significant effect on the experimental group in comparison to the control group. In association, data processing was made using the SPSS WINDOWS 25.0. For the verification of program effect, this study carried out a matched pairs t-test to know pre- and post-test mean differences in career maturity between the two groups. As a result, it was found that the experimental group's post-test scores for factors of career maturity like vocational desire, vocational interest, career confidence, career independence, career involvement and information processing ability improved in a statistically significant fashion from their pre-test scores for those factors. Besides, the study conducted an analysis of descriptive statistics, especially in terms of mean and standard deviation, on the experimental group's self-reports for each session as part of performance assessment of that group. The analysis found that during participation in the career coaching program, the experimental group was high in the level of behavioral objectives they would achieve at each session as well as in satisfaction of the program itself.