<p>
Not really, unless you happen to pick a lab and a project exceptionally early. The F31s are different from the NSF GRFP in that what’s being evaluated is the training potential for the specific proposal and laboratory you submit, rather than being more about you and your impact on the world. The sponsor for your F31 should be your actual graduate advisor, and you should propose what you actually plan to do for your thesis. Many study sections will expect a decent amount of preliminary data in your proposal.</p>
<p>In many programs, it’s unnecessary to apply for an F31 until third year, because your programs will generally fund you via program funds or training grants through the end of year two. You won’t be transferred to your PI until then. Many programs also either have proposal-writing courses or structure the qualifying exam such that it’s basically ready to be submitted as an F31. Those are very useful things.</p>
<p>The due dates for F31s are currently April 8, August 8, and December 8. If you wanted to start your F31 as soon as your departmental funding ran out, you’d have to apply for the December 8 date during second year. But it’s more important to apply for an F31 when you have a solid proposal with some preliminary data – you only get a limited number of shots at getting the grant.</p>
<p>It would be fine to use a PI from undergrad as one of your reference letters. I did, because I knew that PI wrote me a very strong letter for graduate school.</p>
<p>…incidentally, today (2/1) is the first day of my F31. 
I applied in April of third year.</p>