Unsp fx first MC bone, right hand, subs for fx w nonunion

This code signifies an unconfirmed fracture of the first metacarpal bone (thumb) in the right hand. The "subsequent encounter" indicates the patient is receiving follow-up care for this fracture, and "nonunion" specifies that the bone fragments have failed to heal together after a typical healing period.

Use this code for patients presenting for ongoing treatment of a right thumb metacarpal fracture where the specific type of fracture (e.g., transverse, oblique) was not documented at the initial encounter. This code is appropriate when imaging or clinical assessment confirms that the fracture has not united and further intervention or management is being provided.

• Ensure documentation clearly states "right hand" and "first metacarpal."
• Verify that "nonunion" is explicitly documented, not just delayed healing.
• Confirm this is a subsequent encounter, not the initial treatment.