To pilot a balloon, you must hold a Balloon Pilot Certificate issued by the FAA. There are three different certificates, each requiring specific levels of training.

Student Certificate
This is essentially a "learner's permit."
Requirement: Simply fill out an application.

Private Certificate
This is the basic license. Allows the pilot to carry passengers.
Requirements:
1- Pass a written test.
2- Have a minimum of 10 hours of balloon flight time
3- Pass a flight test.

Commercial Certificate
Allows the pilot to fly for hire and give instruction.
Requirements:
1- Pass a written test.
2- Have a minimum of 35 hours of flight time, including at least 20 in balloons
3- Pass a flight test.