<p>Conceptually, the UCs will expect you to pay the EFC determined by filling out the FAFSA, plus take a work-study job for a couple thousand more. That is the baseline. Then they will offer you a combination of federal and state (CalGrant, if applicable) grants and loan options to make up the full cost of attendance. The two options beyond this are special circumstances changing the cost of attendance, and outside scholarships. The rule of thumb is that outside scholarships never (at UC) reduce the EFC number. They are applied to work-study allocation, loans, and grants; hopefully in that order. If someone has experience here to refine the details, chime in.</p>
<p>The point is, it is definitely worthwhile to look into outside scholarships to offset the allocated work-study and loan amounts, which could be around $2-3K (W-S) + up to $12.5K (loans) per year. So scholarships up to $15K per year (depending on your EFC and grants) are worth pursuing.</p>
<p>Note that freshmen with $0 EFC can benefit from up to $8K in outside scholarships (that is 8-16 of those typically $500-$1,000 local scholarships!). Beyond that, while it reduces impact to UC in grant aid, it has no effect on what the student pays.</p>