Mallet finger of unspecified finger(s)

This code signifies a deformity of the distal interphalangeal (DIP) joint, characterized by an inability to actively extend the fingertip due to disruption of the extensor tendon. It results in a characteristic droop of the distal phalanx. This condition is often caused by trauma, such as a direct blow to the fingertip.

Apply this code when documentation confirms a diagnosis of mallet finger, but the specific finger affected is not specified. This is appropriate when the physician's notes indicate "mallet finger" without laterality or digit identification. Supporting documentation would include clinical notes describing the characteristic DIP joint deformity and extensor lag.

• Avoid using this code if the specific finger (e.g., thumb, index, middle, ring, little) is documented; instead, use a more specific code from the M20.01- series.
• Ensure the documentation clearly states "unspecified" or lacks specific finger identification to justify using this code.
• Consider if an external cause code (e.g., W50.- for striking against or struck by another person) is also warranted if the mallet finger resulted from a traumatic event.