Spontaneous rupture of unspecified tendon

This code signifies the sudden, non-traumatic tearing of a tendon without a clear external cause. It indicates that the specific tendon involved in the rupture is not documented or is unknown. This condition typically results in acute pain, swelling, and loss of function in the affected area.

Apply this code when documentation clearly states a "spontaneous tendon rupture" but does not specify the anatomical location of the ruptured tendon. It is appropriate when the physician's notes lack the granular detail to assign a more specific code from the M66 category.

• Avoid using this code if the documentation specifies the tendon involved (e.g., Achilles, rotator cuff); instead, use a more specific M66 subcategory.
• Ensure the rupture is explicitly stated as "spontaneous" or "non-traumatic" to differentiate from traumatic ruptures (S-codes).
• Query the provider for clarification on the specific tendon if possible, to allow for more precise coding.