which each tax rate takes effect are indexed with inflation, so they change each year. 2. The average tax rates are always below the marginal rates, but in 2020 the average at the top of the brackets approaches 37% as taxable income rises without limit. 3. In 2018 , the personal exemption for the taxpayer and dependents was eliminated. With the deduction limitation on state and local property, income, and sales taxes and the existence of payroll taxes (Social Security and Medicare taxes), the 2020 effective tax rate will be higher than 37%. which each tax rate takes effect are indexed with inflation, so they change each year. 2. The average tax rates are always below the marginal rates, but in 2020 the average at the top of the brackets approaches 37% as taxable income rises without limit. 3. In 2018 , the personal exemption for the taxpayer and dependents was eliminated. With the deduction limitation on state and local property, income, and sales taxes and the existence of payroll taxes (Social Security and Medicare taxes), the 2020 effective tax rate will be higher than 37%