The Assessment of Written Expression Adaptivity for Assistive Technology (AWE ADAPT for AT) was developed to examine written expression participation in high school-age clients to aid the identification of assistive technology (AT) tools that can be recommended to optimize written expression. The tool is guided by the Occupational Adaptation (OA) model and measures the constructs of relative mastery (i.e., client's perceptions regarding effectiveness, efficiency, and satisfaction) and adaptive capacity (i.e., perceived helpfulness of existing strategies) as they relate to written expression participation. The purpose of this study was to evaluate the content validity of the AWE ADAPT for AT. Seven content experts were recruited and five reviewed the assessment to determine the item-level content validity index (I-CVI) and scale-level index (S-CVI). The content experts agreed that 28 of the 30 assessment items were essential in assessing written expression participation as noted by an I-CVI score of 0.80 and higher. A scale-level content validity (S-CVI) of 0.92 also established the AWE ADAPT for AT as a content valid measure of written expression participation. After content validation, this tool is now ready for analysis of clinical utility and future construct validation.