ICD-10-CM 2027
ICD-10 code for Cistern
Abnormal findings on diagnostic imaging of skull and head, not elsewhere classified
From the official ICD-10-CM alphabetic index entry “Cistern, subarachnoid”. Page updated September 29, 2026.
About coding Cistern
The ICD-10-CM code for Cistern is R93.0 (Abnormal findings on diagnostic imaging of skull and head, not elsewhere classified).
Within R93 (abnormal findings on diagnostic imaging of other body structures), R93.0 is specifically for abnormal findings on diagnostic imaging of skull and head, not elsewhere classified. Related codes cover abnormal findings on diagnostic imaging of heart and coronary circulation (R93.1), abnormal findings on diagnostic imaging of liver and biliary tract (R93.2), abnormal findings on diagnostic imaging of other parts of digestive tract (R93.3), abnormal findings on diagnostic imaging of urinary organs (R93.4), abnormal findings on diagnostic imaging of other abdominal regions, including retroperitoneum (R93.5), abnormal findings on diagnostic imaging of limbs (R93.6), abnormal findings on diagnostic imaging of other parts of musculoskeletal system (R93.7), abnormal findings on diagnostic imaging of other specified body structures (R93.8) and 1 more.
Don't report R93.0 together with the conditions in its Excludes1 note: intracranial space-occupying lesion found on diagnostic imaging (R90.0).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Don't confuse with (Excludes1 for R93.0)
- intracranial space-occupying lesion found on diagnostic imaging (R90.0)
Common questions about Cistern ICD-10 codes
What is the ICD-10 code for Cistern?
- R93.0 — Abnormal findings on diagnostic imaging of skull and head, not elsewhere classified.
Is R93.0 billable?
- Yes. R93.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R93.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R93.0 as a principal diagnosis.
Is R93.0 a CC or MCC?
- No. R93.0 is neither a CC nor an MCC under MS-DRG v44.0.