The filing requirements for a federal tax return depend on factors such as the taxpayer's income, the taxpayer's age and filing status, the age of the spouse on joint returns, if the taxpayer is claimed as a dependent on someone else's return, earnings from self-employment, and more.
The IRS Interactive Tax Assistant (ITA) Do I Need to File a Tax Return? webpage can walk you through steps to determine your filing requirements.
To determine the requirements for your situation on your own, go to IRS Instruction 1040 and review the following charts:
You can also go to IRS Publication 501 Dependents, Standard Deduction, and Filing Information.
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the webpage or document at the time it is accessed.