R91.8Other nonspecific abnormal finding of lung field

R91.8 is the ICD-10-CM diagnosis code for other nonspecific abnormal finding of lung field. It belongs to category R91 (abnormal findings on diagnostic imaging of lung), block R90-R94 (abnormal findings on diagnostic imaging and in function studies, without diagnosis) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within R91, choose R91.8 (Other nonspecific abnormal finding of lung field) only when documentation doesn't support a more specific option: Solitary pulmonary nodule (R91.1).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 204 (Respiratory Signs and Symptoms, relative weight 0.821), in MDC 04 (Diseases and Disorders of the Respiratory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 793.19 (other nonspecific abnormal finding of lung field).