Background: Telehealth is rapidly expanding, and telehealth-based occupational therapy assessments must be developed and validated to keep pace with this transition. TeleWrite aims to bridge this gap. Objectives: To analyze the tool’s initial psychometric properties using Rasch methods. Method: Internal construct validity and test reliability were analyzed using data from 148 children from first to third grade. Results: Rasch analysis helped to identify that TeleWrite is composed of three separate constructs for rate, accuracy, and fluency. All Infit/Outfit mean square (MNSQ) values fell within acceptable ranges of 0.5 to 1.7 logits. Separation analysis indicated lower but acceptable person separation values for rate (0.68–0.76) and fluency (0.61–0.73), but accuracy scales were in the poor-fair range (0.20–0.60), given sample limitations. Conclusion: TeleWrite is comprised of three separate constructs, showed a good fit with the Rasch model, indicated strong construct and internal validity, and moderate ability to reliably separate abilities of students in terms of handwriting skills.