Tax Year Prior to 2020: Is self employment tax based on income before or after a 401K contribution is made

[sherrie33]

I'm an independent contractor paid on a 1099.  I have a Self-employed 401  do I reduce my earned income by my 401 contribution or do I pay self-employment taxed on income prior to the 401 deduction

[KarenL2]

The self-employment tax is before your 401(k) contributions.  It is based on the net profit on the Schedule C.