The final Republican bill would create seven new brackets, with the top tax rate lowered to 37 percent.

Under previous versions of the bill, that was a millionaires' tax. In the final bill, the top rate would apply to income over $500,000 for individuals and $600,000 for married couples.

The nearly doubled standard deduction would create what Republicans are calling a "zero percent bracket." That benefit, however, would be offset by the loss of personal exemptions.

Below are the new brackets, starting in 2018. They would increase with inflation in later years.

Married filing jointly

10 percent: $0 to $19,050

12 percent: $19,050 to $77,400

22 percent: $77,400 to $165,000

24 percent: $165,000 to $315,000

32 percent: $315,000 to $400,000

35 percent: $400,000 to $600,000

37 percent: More than $600,000

Single

10 percent: $0 to $9,525

12 percent: $9,525 to $38,700

22 percent: $38,700 to $82,500

24 percent: $82,500 to $157,500

32 percent: $157,500 to $200,000

35 percent: $200,000 to $500,000

37 percent: More than $500,000