I always ask my actor friends: "Where exactly are you with your acting career?" Different people get to certain segments of their acting career at different speeds. Many times I encounter actors at an expo where I try to sell them my services. "Get an Actor Website... but wait..." then I hear that they're still in school, they have no headshots, no projects they've worked on, no reel... okay, you're not ready for a website yet, perhaps just get a domain name. ;)
The same applies to your union status. If you feel you're ready, you'll know you're ready. If you can't fill half of a page of your acting resume, perhaps there are still few things you should do first. Trust me, soon you'll have too much stuff for a single page and you'll be emailing me about decreasing the font on the Resume Maker Pro tool in our admin because you want to fit one more skill and one more project. You know who you are. ;)
Also remember that joining the union is not free. As I'm writing this article, the initial fee is $3,000 and then you have to keep paying annual fee of about $200 or more. If you're SAG-AFTRA eligible but haven't paid the initial fee to become union yet, you can still work non-union jobs. And remember (this is the one people often trip up on)... once you become union, you can't work non-union jobs.
When you're ready to move on to bigger and better projects you'll need an agent. Oh, did I mention checking out https://www.agentlist.org yet? No? Go check it out. But I digress. Many agents only represent actors who belong to the union. There's a chance that you might find one who takes you in despite of you being non-union, but you have to understand that he or she will keep hitting walls with limitation for projects, ergo it's much tougher for them to find you your next gig. Being union also give you certain benefits like free classes, workshops and access to other tools to help you grow as an actor. There are two ways to become union.
Some people also call it "being Tafted". It means that you are a non-union actor that got cast in a union, SAG-AFTRA role. This is very rare. In order for this to happen you need to have a rare talent that no other actor in the union possesses. Perhaps you speak a rare language or you can walk on a tight line. If the producers can find someone who is in a union that can do this, chances are you won't become union this way. Tafting someone requires the production to prove to SAG-AFTRA that they couldn't find a union actor who was right for the part. In other (also very rare cases) you could ask to audition for a part, maybe you saved someone's life and they owe you? I'm not one to cross this off completely. One thing for certain, if you accept the part and are Tafted, you are required to become union within a year.
Receive three SAG-AFTRA vouchers
This is much easier and faster than Tafting. A voucher is a like a receipt that proves you've worked on a union project at the SAG-AFTRA rate. If you obtain three vouchers from working, then you can become SAG-AFTRA eligible. In order to get these vouchers, you can work non-union as an extra and ask if you can talk to the producer for a voucher. They might or might not have them, but if you keep asking on different sets, eventually you'll get there.
If you're in a rush and have some extra cash, you can cheat the system a little. Get approval from SAG-AFTRA to produce your own short film. Check the official SAG-AFTRA website to make sure you meet all requirements. This is fairly easy to do. In fact, I strongly recommend connecting with other actors and filmmakers on Stage 32 to do this so you can gain access to some of their equipment and have access to other actors for your story. You can even hire a screenwriter so that you have a script to act out. Do that three times and you're an actor / producer who is SAG-AFTRA eligible.