What does the 'Age Statement' mean on my whiskey?

What does the 'Age Statement' mean on my whiskey?

The age statement a bottle of American whiskey is the length of time, rounded down to years, that the whiskey has spent aging in the barrel. In the case where whiskey has been mixed or blended the age stated is that of the youngest whiskey.  Although not required by law for bourbon or rye to carry an age statement, many bottles state their age to show provenance and to distinguish the quality of their product. Here are a few examples;

Age statement 18 years

Elijah Craig 18 Year Old Single Barrel 1990 was barrelled on 9/11/90 from barrel no. 3907 and bottled in 2008 .

https://www.nativespiritsonline.com/products/elijah-craig-18-year-old-single-barrel

Age statement 15 years

George T Stagg 2015 was blended from barrels from the same distillery but from different warehouses / rickhouses. The youngest barrel was 15 years and 1 month old. https://www.nativespiritsonline.com/products/george-t-stagg-2015

Age statement 4 years

Gifted Horse Bourbon is a blend of 3 bourbons, the oldest (38.5% of its content) is 17 years old, the other 2 bourbons are 4 years old.

https://www.nativespiritsonline.com/products/gifted-horse

NAS or No Age Statement.

The producer (distiller or blender) has decided not to release an age statement. This could be because the bottle has barrels that are very young in the mix, because the distillery / producer / bottler can no longer source a large enough supply of age stated bourbon like in the case of Black Maple Hill NAS or simply because they done want to say.