Does everyone have to send in tax return forms?

<p>Does everyone have to send in tax returns, or do they just make requests to certain people for them? And if everyone has to send them in, is it okay if they get in a little late, seeing as how the Feb 15 deadline has already past? (I already submitted FAFSA and PROFILE before deadline)</p>

<p>The web site says you "may" be asked to submit tax retrurns</p>