ICD-10-CM > M00-M99 > M65-M67 > M66 > M66.2 > M66.27 M66.27 Spontaneous rupture of extensor tendons, ankle and foot Non-Billable/Non-Specific Codes M66.271Spontaneous rupture of extensor tendons, right ankle and footM66.272Spontaneous rupture of extensor tendons, left ankle and footM66.279Spontaneous rupture of extensor tendons, unspecified ankle and foot