No matter the size of your production, the Screen Actors Guild (SAG) wants to work with you if you are employing their members. They have agreements for films of all sizes, and each agreement reflects what they believe are fair terms and wages for their members in relation to the size of the budget. They even have a SAGIndie division that makes it easier for independent filmmakers to work with SAG actors.
In pre-production, you will want to become SAG signatory if you plan on hiring SAG actors. This means filling out applications that detail the status and size of your production and how many roles are to be cast, etc. You will be appointed a SAG representative with whom you will submit your applications and provide paperwork through the production.
SAG does require a deposit of a percentage of your budget in order to cover the pay for the actors. This money is not used to pay the actors. Instead, it sits in a bank account and accrues nominal interest as you are filming. This can be tough on independent filmmakers as their deposit requirements tend to be very high. I like to earmark those funds for post production, which in a strange way, actually helps me to make sure I don't use all my money up on production. Out of sight, out of mind.
In post production, you will have to submit a bunch of wrap paperwork detailing how many days each actor worked and the pay they earned. Once this paperwork has been reviewed and signed off by SAG, your deposit is returned, with interest. If there is any outstanding pay to the actors then your deposit is at risk. So pay your actors!
During this past year, SAG and thehave been waging a war over contract negotiations. Threats of a strike have been looming over the industry for months. Personally, I find it hard to swallow that they would consider striking during a recession. I understand their concerns but there has to be another way than putting thousands of people out of work (because when they strike, no one works, including crew and vendors, etc.) and harming the economies of cities like Los Angeles -- which is running out of money as it is! Please SAG, don't strike!