But first, fifth-digit requirements on NOS go into effect next year. When a patient experiences accumulation of air or gas in the pleural space, which may occur spontaneously or as a result of trauma or a pathological process, the pulmonologist would likely detect a pneumothorax diagnosis. You would code this with the ICD-9 code 512.x (Pneumothorax). ICD difference: Pay attention to the type of pneumothorax tidentified in the documentation. Category J93.x excludes some commonly seen forms of pneumothorax: postprocedural (J95.81), traumatic (S27.0), etc. Coder tips: Under ICD-9 2011, you used 512.8 (Other spontaneous pneumothorax) to report an acute, chronic, or NOS pneumothorax (J93.1 in ICD-10-CM). For ICD-9 2012, you should choose from a range of five-digit 512.8x codes: These diagnoses will revert back to other spontaneous pneumothorax (J93.1) when ICD-10 takes effect in 2013.