Hi,
I got four W-2 Forms from four different places including university when I worked as TA. One of W-2 form which I missed was $1000 (income) when I did small project during one month after I graduated.

When I filed for taxes( I already sent 1040NR-EZ), I missed this.
Can I file for this income next year when I do tax filing or what I have to do?

Is it a problem?