I am a graduate student and I received a fellowship. I reported the fellowship as my income but I was not issued a W2. Will the IRS ask for a W2?

I am filing via postal mail and in the past when I was working as a teaching assistant I attached the W-2 that was issued to me. But this year I was on a outside scholarship and was not issued a W-2. Will IRS ask for a W-2? But I don't have one; will this create problems for me?