Spontaneous rupture of other tendons, unspecified upper arm

This code signifies a non-traumatic tear of a tendon in the upper arm, excluding the rotator cuff, biceps, or Achilles tendons. It indicates that the specific tendon involved is not documented, and the rupture occurred without an external force or injury.

Apply this code when documentation specifies a spontaneous rupture of an unspecified tendon within the upper arm. This is appropriate when the physician explicitly states "spontaneous rupture" and does not identify a specific tendon (e.g., triceps, deltoid) or a traumatic event.

• Ensure documentation clearly states "spontaneous" and not "traumatic" to differentiate from injury codes.
• Avoid using this code if a more specific tendon (e.g., triceps tendon) is identified; instead, use the appropriate M66.8x_ code for that specific tendon.
• Query the provider if the documentation indicates a rupture but lacks specificity regarding the cause (spontaneous vs. traumatic) or the exact tendon involved.