Direct quotes from the gocoastguard.com website:
The Coast Guard Reserve offers many programs to fit your needs:
Split Training Program - If you are a qualified applicant between the ages of 17 and 30, this program will allow you join the Coast Guard Reserve without interrupting your busy schedule. Basic and Advanced Training take place over two subsequent summers or as availability permits. Between Basic and Advanced Training, Reservists in this program are paid to participate at their assigned unit one weekend per month.
Petty Officer Selectee Program - If you have no prior service and are between the ages of 17 and 30, you may qualify for this program. You will attend eight weeks of Basic Training at Cape May, NJ, followed by Class 'A' School (advanced training). Class 'A' schools range in length from five weeks to five months depending on career field. Schooling is guaranteed before return to civilian life.
Accelerated Petty Officer Program - If you are ready to learn an exciting new career field, have a desire to serve and are between the ages of 30 and 35, (we are currently accepting age waivers up to age 39), this may be the program for you. With a minimum of two years college (or equivalent), you will be eligible to enlist at a higher pay grade, attend just two weeks of Reserve Basic Indoctrination, then receive advanced training in a critical field (Boatswain Mate, Machinery Technician, Operation Specialist or Marine Science Technician). Valuable training, an opportunity to serve, and immediate advancement are just a few of this program's many advantages.
Direct Petty Officer - If you have no prior service and are between the ages of 21 and 35 with a civilian skill relating to a Coast Guard job, you may qualify. Members enlist in the Coast Guard Reserve as Petty Officers with immediate responsibility and increased pay.
Prior Service Program - If you have prior military experience and are between the ages of 21 and 40, (we are not currently accepting prior service age waivers up to age 45), you may qualify for this program. Depending on specialty and separation code, veterans are eligible for enlistment in the Coast Guard Reserve. Training opportunities are available to members that possess military skills that do not correspond with Coast Guard ratings. Many veterans choose this program to maintain military skills and earn points toward retirement eligibility.