CanyonAg77 said:
Don't know how accurate this is, but note that in NH and AK, concealed carry is allowed at age 16.
Also note that Maryland has an offical age of 18 for CC, but in reality, almost no one gets a CC permit. And those that are issued are usually work related. If you get a permit because your job is handling money, you have to store the pistol when you get off work.
http://dustinsgunblog.blogspot.com/2009/10/map-of-minimum-age-to-conceal-carry.html
I suspect that there are some variations in some states that aren't captured on that map because it would make it really complex. If you travel, READ UP on the laws in the state you are traveling to. For instance in Idaho:
There are literally three types of CC:
-Constitutional Carry: Anyone 18 or older both resident or non resident can Constitutional Carry (no permit required) OUTSIDE of city limits. To Constitutional Carry carry INSIDE a city limit you must be both an Idaho resident and over 21.
-Basic CCW permit: Must be over 21 and can carry CCW anywhere not prohibited (schools, courthouses, etc.) Both residents and non residents can get a permit.
-Enhanced CCW permit: Must be 21 or over, take more extensive training and mental health record check. This permit does two things. 1) Opens up more states with reciprocity including WA, NV. and a few others. 2) Allows one to campus carry. Both residents and non residents can get an Enhanced CCW permit.
One wrinkle in this law is that if you are 18-20 you can meet the requirements for the Enhanced CCW permit and they will issue you a basic carry permit. When you turn 21 you come back and they issue you the enhanced permit.
The tl/dr version: Make sure you are aware of the laws in the state you travel to. I am sure Idaho is not the only state that has some interesting variations in how and when you can CC.