The law sets the self-employment tax rate as a percentage of your net earnings from self-employment. This rate consists of 12.4% for social security and 2.9% for Medicare taxes.
The maximum amount of net earnings subject to the 12.4% social security portion of the self-employment (SE) tax for 2018 is $128,400. All net earnings of at least $400 are subject to the Medicare part of the tax.
Self-Employment Income* is income from: