How much do I need to earn in income tax to file in 2019

[xmasbaby0]

Do you have a W-2 with an amount in box 2?  Even a small amount of income could get you a tax refund.  Or did  you work for cash as an independent contractor?

DO I NEED TO FILE A TAX RETURN?

https://www.irs.gov/help/ita/do-i-need-to-file-a-tax-return

[Hal_Al]

Simple answer: $12,200 the filing threshold for a single person who is not somebody else's dependent. That's when you have to file. 

But taxes aren't simple. If you have more than $400 of self employment income, you have to file.  Dependents with unearned income have to file at $1100.  There are refundable credits available to people with earned income who are not required to file but should.  You will want to file to get back any withholding in box 2 of your W-2. 

There is no minimum you have to make to file, when not legally required to.  The earned income credit starts at $1 of income and the refundable portion of the child tax credit starts at $2500.