Almost everyone needs to file an income tax return. There are exceptions made for people who earn relatively small incomes.
You must also file your 2018 tax return if any of the following apply to you:

1. Single (under age 65 - $12,000 ; over age 65 - $13,600)
   
2. Head of Household ( under age 65 - $18,000; over age 65 - $19,600)
   
3. Married filing separately ( any age -  $5,000 )
   
4. Married filing jointly (both under age - 65 $24,000; one over age 65 - $25,300;  both over age - 65 $26,600)
   
5. Qualifying Widow(er) with Dependent Child (under 65, - $24,000; over 65 - $25,300)
   

Gross income includes all income that is not tax exempt, and even if a taxpayer's gross income is less than the amount required for filing a return, there are other factors which will require that a tax return be filed. Those other factors are:

• An individual owes any special tax to the IRS, such as AMT, IRA tax penalties, or FICA tax on tips.
• Individual received any advance earned income credit payments from an employer.
• Individual had net earnings from Self-Employment of $400 or more.
• Individual is a non-resident alien with a business or tax liability not covered by withholding.

Even an individual with gross income under the limit for his or her filing status still may want to file a return to get back income taxes withheld from earned income above the tax liability on the tax return. Essentially, to get his or her income tax refund, a return will need to be filed.