SEP IRA will likely give you the most available money to shelter depending on your income. As the fixer said, it's 20% of self employed net income. If you only made $20K it will be lower than a SIMPLE IRA would allow. If you made $250K net, you can do up to the $50K limit for all tax deferred vehicles. My numbers aren't perfect, but it should give you an idea of how powerful the SEP IRA is vs. the others. I think the SIMPLE IRA is limited to $12K/year, but not positive on that one.