"if you end up at $90,000 from your company, your whole income should be liable for FICA just like a BigCo worker's"<p>Why?  By that reasoning, shouldn't profits that BigCo shareholders make (which become personal income when they realize them) subject to FICA?  I'm both an owner and an employee -- why shouldn't some of my income be FICA-taxable as the output of "labor", and some be non-FICA-taxable as business profit?