A bill to define the affirmative defense of insanity and to provide a procedure for the commitment of offenders suffering from a mental disease or defect, and for other purposes.

Amends the Federal criminal code to make it an affirmative defense to a Federal prosecution that at the time of the offense the defendant, as a result of mental disease or defect, lacked entirely the ability to understand the nature and the quality of his acts and to distinguish right from wrong.

Places the burden of proving insanity on the defendant.

Requires the court to hold a hearing to determine the present mental condition of the defendant. Directs the court to commit such person to the custody of the Attorney General upon a finding by a preponderance of the evidence that the person is presently suffering from a mental disease or defect, rendering him mentally incompetent. Directs the Attorney General to hospitalize such person in a suitable facility. Provides that when the defendant has recovered and is able to understand the nature and consequences of the proceedings against him, the court will order his release and set a date for trial.

Authorizes a special verdict of "not guilty only by reason of insanity" for any criminal defendant who raises the issue of insanity by notice as provided by Rule 12 of the Federal Rules of Criminal Procedure.

Provides for the hospitalization of persons found not guilty only by reason of insanity, convicted persons, imprisoned persons, and persons due for release who are found to suffer from mental disease or defect.

Allows for discharge when such person is found to have recovered. Requires reimprisonment of any such person for whom a term of prison sentence has not yet expired.