800.66 — Open fracture of vault of skull with cerebral laceration and contusion, with loss of consciousness of unspecified duration

800.66 is an ICD-9-CM diagnosis code for open fracture of vault of skull with cerebral laceration and contusion, with loss of consciousness of unspecified duration. ICD-9-CM was retired for U.S. claims on October 1, 2015, when ICD-10-CM took over.

The CMS General Equivalence Mappings translate it to 2 ICD-10-CM codes, such as S02.0XXB (Fracture of vault of skull, initial encounter for open fracture) and S06.339A (Contusion and laceration of cerebrum, unspecified, with loss of consciousness of unspecified duration, initial encounter). All of these are approximate matches, so review the record to pick the right one. Some mappings are combinations: more than one ICD-10 code is needed to fully express the ICD-9 code.