These age ranges are taken directly from regulations, or the annual reports to Congress.
As with everything in early CAP, some Wing Commanders did not strictly adhere to national regulations, and allowed younger cadets to join.
Cadet Age Ranges
15-18 years old, in the last two years of high school
15-18 years old
15-20 years old
14-21 years old
13-21 years old
In the Seventh Grade-21 years old
Completed the Sixth Grade*-21 years old
*Splitting hairs detail: the rule for "completed the sixth grade" was in effect from 1977 through the mid-1990s. Over the years from the 1990s to the present the minimum age has varied ever so slightly, and it is difficult to pin down exact time frames. For instance, in the mid-90s the wording was briefly changed to "completed the fifth grade", then went back to completed the sixth grade. The current minimum age is 12, with no specific grade requirement.
Some in-school cadet programs do allow sixth graders to participate.
CADET AGE RANGES
New cadets being sworn in to Squadron 605, PA Wing circa mid 1960s