I just received a 1099-MISC for exactly $600, but I had already filed my federal and state tax returns. Do I need to file amended returns including that income?

I saw another question that asked about sending 1099-MISCs for paying someone exactly $600. I assume the answer to this question is the same (necessary for equal to or greater than $600), but I figured I'd check in case I don't have to file amended returns.