President Barack Obama is proposing cutting the corporate tax rate in the United States from 35% to 28% and closing loopholes, as part of a larger push for tax reform.
The United States currently has one of the top corporate tax rates in the world, but loopholes and other subsidies mean many companies pay a much lower effective tax rate.
Republicans also propose lowering rates, but Mr Obama's plan is thought to have few chances of becoming law.
The BBC reports that corporate taxes contributed about 12% of US federal profits last year. Removing the tax loopholes would be likely to raise tax revenues overall.