Case: Tarsal Coalition is a musculoskeletal deformity of the lower limb with a progression that is often asymptomatic until ossification of the calcaneoavicular coalition in the second decade. We report a novel case of a patient symptomatic before ossification of the coalition with resolution of symptoms coinciding with visual appreciation of the condition. Conclusion:This case demonstrates two unique components of the development of tarsal coalition that are not well described in the literature currently: The rapid development of bilateral calcaneonavicular coalitions and transition from symptomatic to asymptomatic as the coalitions matured. Check for updateswith activity. Prior to this, she did not have any past medical history. Her biological father had a history of tarsal coalition. The plan during this time was to consult orthopedics for additional examination. The initial orthopedic examination showed increased tightness in her hamstring muscle and gastrocnemius bilaterally. Examination of the feet revealed flat straight feet with full range of motion of her hindfoot and midfoot. Gait, coordination, and balance were normal. X-ray radiographs were taken at this visit and were unremarkable (Figure 1A and Figure 2A). The patient's family was given instructions to start a hamstring and gastrocnemius stretching regime for the patient and orders to use orthotics in her shoes.13 months later at age 10, the patient presents to the emergency department with an injury to her left great toe. X-ray radiographs taken during her ED visit did not show any structural damage to her great toe but did show anomalies in the tarsal bones that prompted imaging of the uninjured foot. Imaging was reviewed at her next orthopedic visit several months later and indicated bilateral calcaneonavicular coalition that were not present on radiographs during initial