Pre-emptively asking for a LOR

[Owego]

So at the end of this school year I will be leaving my current city where I am a research assistant for a professor. I plan to apply to PhD programs in 1-2 years. I'm sure he would write me a great recommendation, but maybe it wouldn't be as good if he wrote it in 1-2 years. Would it be appropriate to go to him before I leave the job and ask him to write a recommendation that he would keep on reference until it came time to apply?

[Canis]

Yes!

But here's how I would do it. Apply for something. Doesn't matter what, little scholarship, grant, something - and ask three people to write you letters. Get your letter writers for your PhD program now. When that's done, thank them, tell them you would like to use them as references for PhD in 1-2 years, so save the letter. Send them nice cards saying thank you and then stay in touch, an email update every few months letting them know what you're up to or asking them for advice,,, something to keep you alive in their minds.

And when you do apply they will need to update the letters anyway, and you might have new people you want to ask by then, but just in case - I agree it's smart to get them to write now.