If you have a W-2 you do not "have" to file but if there are any amounts in boxes 2 or 17 of that W-2 you can file to get a refund of the tax withheld. If your income was from self-employment then you are REQUIRED to file and pay self-employment tax for Social Security and Medicare.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**