there are income limitations. one is based on filing status. one is based on whether or not the business income is from a Specified Service Trade or Business. The IRS can deny the deduction if a previous W-2 employer is now treating you as an independent contractor. this can be rebutted,
the code section is a couple of pages. the Regulations which fill out what the code says are several hundred.
here's a link to the code section 199A if you're interested.
https://www.law.cornell.edu/uscode/text/26/199A
