To amend title 18, United States Code, to prevent minors from gaining unsupervised access to loaded firearms or to unloaded firearms and ammunition for such firearms.

Amends the Federal criminal code to prohibit any person from leaving a loaded firearm or an unloaded firearm and ammunition in a way that is likely to be accessible to a juvenile, unless the person has given the juvenile permission to possess the item and the possession is under the supervision of an adult who is not prohibited by Federal, State, or local law from possessing a firearm.

Requires: (1) each licensed dealer to post conspicuously at his or her place of business a copy of such provision in block letters that are not less than one inch in height; and (2) the Secretary of the Treasury to ensure that such provision appears on the form required to be obtained by a licensed dealer from a prospective transferee.

Sets penalties for violations of this Act.