ICD-10-CM 2027
ICD-10 code for lung mass
From the official ICD-10-CM alphabetic index entry “Mass › lung”. Page updated September 29, 2026.
About coding lung mass
The ICD-10-CM code for lung mass is R91.8 (Other nonspecific abnormal finding of lung field).
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.
Common questions about lung mass ICD-10 codes
What is the ICD-10 code for lung mass?
- R91.8 — Other nonspecific abnormal finding of lung field.
Is R91.8 billable?
- Yes. R91.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R91.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R91.8 as a principal diagnosis.
Is R91.8 a CC or MCC?
- No. R91.8 is neither a CC nor an MCC under MS-DRG v44.0.