Currently receiving medication for the treatment of tardive dyskinesia

Have a neurological condition other than tardive dyskinesia that may interfere with assessing the severity of dyskinesias

Have a serious untreated or undertreated psychiatric illness

Have recent history or presence of violent behavior

Have unstable or serious medical illness

Have evidence of hepatic impairment

Have evidence of renal impairment

Have known allergy to any component of SD-809 or tetrabenazine

Has participated in an investigational drug or device trial and received study drug within 30 days

Have acknowledged use of illicit drugs

Have a history of alcohol or substance abuse in the previous 12 months

Aim to Reduce Movements in Tardive Dyskinesia