A framework law on preschool education in Bosnia and Herzegovina from 2007 requires all preschool institutions to apply and practice inclusion as well as the compulsory preschool education in a year before children start school. The same law emphasizes that children with developmental disabilities should be included in preschool institutions according to programs adapted to their individual needs. Namely, the goal of applying inclusion in kindergartens is directed towards giving every child the opportunity to progress following their abilities. In that sense, to realize inclusion it is necessary to provide important preassumptions such as curriculum, methods of work, didactic tools, professionally educated team, and permanent assistants in individual assistance. Children with developmental difficulties deal with additional discrimination because most preschool institutions do not have the above-mentioned preassumptions for work and they are often excluded from the educational process. To find the solution to this problem, the focus of this paper is aimed at choosing a curriculum that will enable each child with an equal opportunity in life. In this context, a group of experts who completed the Montessori specialization have created the Integrated Preschool Adaptive Curriculum (IPAC) that is intended for inclusive kindergarten groups. The basis for its development was the contextual and dynamic assessment of abilities, knowledge, and skills of children who attended kindergarten a year earlier and worked according to the methodology of Montessori teaching and techniques. In this paper, we intend to present the results of a three-year study that was based on examining the impact of the Integrated Preschool Adaptive Curriculum (IPAC) on children's readiness to go to school. Readiness in this context considers reaching a certain degree of maturity in cognitive, socio-emotional, and physical development as well as in specific abilities in the cultural, hygienic, and work habits domain.