Unsp fx upper end of l humerus, subs for fx w nonunion

This code signifies a left humerus fracture, specifically in the upper end, that has not healed properly (nonunion). It is used when the patient is receiving active treatment for this nonunion, such as surgical intervention or other medical management, after the initial fracture encounter.

Apply this code for follow-up encounters where a patient is being treated for a previously diagnosed unspecified fracture of the upper end of the left humerus that has failed to unite. This includes scenarios like surgical repair of the nonunion, cast changes, or medication management specifically addressing the nonunion.

• Ensure documentation clearly states "nonunion" and specifies the left humerus, upper end.
• Verify this is a subsequent encounter for active treatment of the nonunion, not a routine follow-up for a healed fracture.
• Always sequence this code after the appropriate external cause code, if applicable, to describe the mechanism of injury.