Unsp nondisp fx of 1st cervcal vert, subs for fx w nonunion

This code describes a fracture of the C1 vertebra (atlas) that is not displaced and whose specific type is not documented. It indicates that the fracture has failed to heal properly, resulting in a nonunion, and the patient is presenting for follow-up care related to this ongoing issue.

Use this code for patients presenting for subsequent treatment of an unhealed, nondisplaced, unspecified C1 fracture. Documentation should clearly state "nonunion" and specify the encounter as follow-up care for the fracture. This code is appropriate when the initial fracture type (e.g., Jefferson, anterior arch) is not specified in the medical record.

• Ensure documentation explicitly states "nonunion" and "subsequent encounter" for accurate code selection.
• Do not use for initial encounters or for fractures that are healing normally; specific codes exist for those scenarios.
• Verify laterality if applicable for other cervical fractures, though C1 is a single bone.