To determine whether you need to file a federal income tax return, you will need to ask yourself the following questions:
Is my gross income over the limit according to the chart of filing requirements for most people, based on my filing status and age?
Can I be claimed as a dependent by another person? If so:
What was my unearned income
What was my earned income
What was my gross income?
If married, is my spouse filing separately and itemizing deductions?
Did I have at least $400 from self-employment?
Do I owe any special taxes?
Did I receive an advance earned income credit payment from my employer?
Based on your answers to the above questions, you can determine whether you are required to file a return.
To determine whether you should file a return, even if you are not required to file, you should see whether you qualify for any special tax benefits, such as the earned income credit. And you should go through the exercise of calculating your tax to see if too much tax may have been withheld from your pay. In either case, by filing a return you can get a refund.