Introduction: This article presents an instrument that measures the assistive technology proficiency of teachers of students with visual impairments and their identification with a community of practice that values assistive technology. Teachers' deficits in assistive technology proficiency negatively impact students who are visually impaired by stunting the development of assistive technology skills, ultimately resulting in poorer postsecondary education and employment outcomes. Identification with a community of practice that values assistive technology may be supportive of the technological proficiency of teachers of students with visual impairments. Method: Assistive technology proficiency and community of practice identification dimensions were defined and outlined in rubric-like "construct maps." A survey that was created to place teachers of students with visual impairments within each construct map was completed by 33 Californian teachers. Survey performance was evaluated by estimating Rasch models, which provided information on relative question difficulty and question performance. Results: Estimated question difficulties revealed expected patterns. Only two survey questions performed irregularly (infit 1.33). Internal reliability was good (Cronbach's Alpha 0.80) for assistive technology proficiency, and acceptable (Cronbach's Alpha 0.70) for community of practice identification. Discussion: The findings suggest the survey reliably measured the assistive technology proficiency and identification with a community of practice that values technology in this sample of teachers. Utilization of this tool may enable the objective evaluation of assistive technology proficiency of teachers pre- and post-training. Implications for practitioners: Creation of a reliable instrument that measures these constructs will support investigations in how one relates to the other, and will consider how professional development may be designed to better support the use of assistive technology by teachers.