ICD-10-CM > M00-M99 > M65-M67 > M66 > M66.8 > M66.82 M66.82 Spontaneous rupture of other tendons, upper arm Non-Billable/Non-Specific Codes M66.821Spontaneous rupture of other tendons, right upper armM66.822Spontaneous rupture of other tendons, left upper armM66.829Spontaneous rupture of other tendons, unspecified upper arm