what does marginal rate mean
A marginal tax rate is the tax rate an individual would pay on one additional dollar of income. Thus, the marginal tax rate is the tax percentage on the last dollar earned. In the United States in 2013, for example, the highest marginal federal income tax rate was 39.6%, applying to earnings over $400,000. Earnings under $400,000 that year had a lower tax rate of 33% or less.