White House officials say the centrepiece of Wednesday's announcement will be a sharp reduction in the business tax rate, from 35% to 15%.
Economists say the tax cuts will add trillions of dollars to the deficit over the next decade.
But Treasury Secretary Steven Mnuchin has said the tax plan "will pay for itself with economic growth".
The much-discussed border tax that would put a tariff on imports - favoured by House Speaker Paul Ryan - will not be in the plan.