Purpose: This project will develop the SIS-C Supports Planning Process, an associated Teachers Manual, and an online Fidelity of Implementation System that will enhance the knowledge and skills of teachers to use the results of a completed Supports Intensity Scale-Childrens Version (SIS-C) assessment to design supplementary aids and services to promote access to the general education curriculum for students with intellectual disability (ID). The SISC was the first standardized measure of supports needs of children with ID, developed with a previous IES Goal 5 Measurement grant (co-PIs: Hughes, Thompson, & Wehmeyer; 2011-2015). Educators need tools and strategies to enhance their knowledge and skills to use SIS-C assessment data to inform supports planning for students with ID in general education. Setting: Elementary schools in Kansas and Illinois, some of which participated in data collection for the development of the SIS-C assessment. Sample: Teacher participants will be special education teachers that provide supports and services for students with ID. Student participants must have a primary educational classification of ID, consistent with the norming sample for the SIS-C and will be selected to be representative of the ranges of intellectual functioning (mild, moderate, severe/profound) for which the SIS-C was normed. Intervention: The SIS-C Supports Planning Process will enable teachers to develop knowledge and skills to (1) identify a students support needs by interpreting SIS-C assessment data, (2) problem solve with appropriate stakeholders to identify specific supplementary aids and services that will enhance learning and participation in the general education curriculum (3) implement the identified supplementary aids and services, and (4) evaluate the impact of the supplementary aids and services on learning and participation outcomes, making adjustments as needed. Research Design and Methods: We will use design research methodology to provide a systematic framework for the development process. This project will be broken into four phases associated with our four primary research questions: (1) develop the SIS-C Supports Planning Process (i.e., components, content, mode) through an iterative process with end-user focus group feedback; (2) refine and improve upon the initial SIS-C Supports Planning Process and evaluate feasibility and usability using single-case design; (3) extend evaluation of the full SIS-C Supports Planning Process to examine fidelity of implementation and the measurement of teacher and student outcomes using a repeated measures MANOVA design; and (4) conduct a pilot study to examine the impact on teacher and student outcomes using multi-level models. Key Measures: Teacher knowledge and skill outcomes will be measured using the SIS-C Knowledge, Skills, and Use Survey and data collected on classroom ecology and teacher behavior using the MS-CISSAR data collection system. Student outcomes related to access to the general education curriculum will be measured with the Access CISSAR, an add-on module to the MS-CISSAR. Fidelity of implementation data will be collected by independent observers using the Online Fidelity of Implementation System. Data Analysis: The four phases of the project will yield unique data on feasibility, fidelity, and the impact on teacher and student outcomes. Data collected during each phase will be analyzed using best practices, linked to its associated design and research questions.