Final answer:
The motorcycle endorsement can be added to your license after passing a basic rider course. The age requirement for adding a motorcycle endorsement to your license varies by state.
Step-by-step explanation:
The motorcycle endorsement can be added to your license after passing a basic rider course. Taking the driver's test is not sufficient to obtain a motorcycle endorsement. Additionally, the age requirement for adding a motorcycle endorsement to your license varies by state. In some states, you can add the endorsement when you're 18 or older, while in others, you need to be 21 or older.