851.66 — Cerebellar or brain stem laceration without mention of open intracranial wound, with loss of consciousness of unspecified duration

851.66 is an ICD-9-CM diagnosis code for cerebellar or brain stem laceration without mention of open intracranial wound, 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 S06.379A (Contusion, laceration, and hemorrhage of cerebellum with loss of consciousness of unspecified duration, initial encounter) and S06.389A (Contusion, laceration, and hemorrhage of brainstem with loss of consciousness of unspecified duration, initial encounter). All of these are approximate matches, so review the record to pick the right one.