Unsp opn wnd r bk wl of thorax w/o penet thor cavity, init

This code signifies an open injury to the right posterior chest wall that has not been specified further, such as a laceration or puncture wound. Importantly, the injury does not extend into the thoracic cavity, meaning the pleura and lungs are not affected. This is an initial encounter for the injury.

Use this code for a patient presenting with an uncharacterized open wound on the right side of their back, over the rib cage, where clinical assessment or imaging confirms no penetration into the chest cavity. This is appropriate for the first time the patient is seen for this specific injury.

• Ensure documentation clearly states "right back wall of thorax" and explicitly rules out thoracic cavity penetration.
• If the wound type (e.g., laceration, puncture) is specified, a more precise code from the S21.2 series should be used.
• Append subsequent encounter or sequela characters (D or S) for follow-up care or complications, respectively.