Bell's Palsy ICD-10-CM codes

Bell's palsy is G51.0. The code has no laterality, so right- or left-sided involvement is recorded in the documentation only. Facial palsy and facial nerve paralysis without the term Bell's also index to G51.0, so idiopathic facial weakness lands on the same code. G51.9 (disorder of facial nerve, unspecified) is for non-paralytic facial nerve disorders, and other named conditions such as hemifacial spasm and Melkersson syndrome fall within G51.

Facial paralysis caused by herpes zoster (Ramsay Hunt syndrome) is coded to the infection: B02.21 (postherpetic geniculate ganglionitis) or B02.29, not to G51.0. Facial weakness caused by a stroke is a manifestation of the cerebrovascular event and is coded with the stroke (I63.-) or its sequela (I69.-), not as Bell's palsy.

Incomplete eyelid closure from facial nerve weakness can be reported with lagophthalmos (H02.20- by eye and eyelid) when the provider documents and treats it. Corneal exposure treated with lubricants or taping should also be coded when addressed.