S02.91XBUnspecified fracture of skull, initial encounter for open fracture

S02.91XB is the ICD-10-CM diagnosis code for unspecified fracture of skull, initial encounter for open fracture. It belongs to category S02 (fracture of skull and facial bones), block S00-S09 (injuries to the head) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "B" means initial encounter for open fracture: use it while the patient is receiving active treatment for the condition.

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 082 (Traumatic Stupor and Coma >1 Hour with MCC, relative weight 2.2928), DRG 083 (Traumatic Stupor and Coma >1 Hour with CC, relative weight 1.3831), DRG 084 (Traumatic Stupor and Coma >1 Hour without CC/MCC, relative weight 0.9605), DRG 085 (Traumatic Stupor and Coma <1 Hour with MCC, relative weight 2.245), DRG 086 (Traumatic Stupor and Coma <1 Hour with CC, relative weight 1.3067), DRG 087 (Traumatic Stupor and Coma <1 Hour without CC/MCC, relative weight 0.9223) and 3 more, in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 24 (Multiple Significant Trauma), 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 803.50 (other open skull fracture without mention of injury, unspecified state of consciousness).