Primary blast injury of unspecified ear, initial encounter

This code signifies damage to an unspecified ear resulting directly from the sudden pressure changes of a blast wave. This injury is typically characterized by barotrauma, such as tympanic membrane rupture, ossicular chain disruption, or inner ear damage, occurring at the time of the blast event.

Apply this code for patients presenting with ear injuries directly attributable to a primary blast exposure, such as from an explosion. Documentation should clearly state the mechanism of injury as a blast and specify that it's the initial treatment encounter for this condition.

• Ensure documentation specifies "primary blast injury" as opposed to secondary (e.g., projectile) or tertiary (e.g., impact) blast injuries.
• This code is for an unspecified ear; if the specific ear (right or left) is documented, use the more specific codes (S09.311A or S09.312A).
• The "A" suffix indicates an initial encounter for active treatment of the injury.