So, here's what taxpayers need to keep in mind: Even if Ocasio-Cortez's 70% tax bracket were implemented, Americans who earn more than $10 million per year would only pay 70% on income above $10 million. The rest of their income would be taxed at the lower, existing tax brackets. Also bear in mind that this would only apply to taxable income in excess of $10 million. That means if a taxpayer had $12 million in gross income and claimed $2 million in deductions (such as large charitable donations), he or she would not be affected by the new tax bracket.

https://www.fool.com/taxes/2019/01/24/alexandria-ocasio-cortezs-70-tax-plan-what-all-ame.aspx