MPAA — United States

The American rating system is run by CARA (the Classification and Rating Administration) under the MPA. Unlike most European systems it is voluntary industry self-regulation — ratings are enforced by exhibitors, not by law.

Rating tiers

Tier	Meaning
G	General audiences
PG	Parental guidance suggested
PG-13	Parents strongly cautioned — under 13
R	Restricted — under 17 requires accompanying adult
NC-17	Adults only

What this means for ads and trailers

US trailers are separately approved and tagged ("approved for appropriate audiences" / "all audiences"), and exhibitors match trailer placement to the feature's audience. The voluntary nature of the system doesn't lower the bar — studio and exhibitor policy enforce it commercially instead of legally.

Official source: www.filmratings.com

Tip

The DCProof Age Report estimates the MPAA tier of your ad or trailer, with timecoded findings per criterion.