Despite recently passed tax reform, America’s income tax system remains progressive, with top earners expected to pay a higher share of income taxes in 2018. Lower-earning Americans will pay a smaller share of income tax next year.

According to estimates from Congress’ Joint Committee on Taxation, the 2018 individual income tax is expected to raise 50 percent of total federal revenue, up from approximately 48 percent in 2017.

The Tax Policy Center, a nonpartisan research group, divided approximately 175 million American households into five income tiers of about 65 million people each. The group considered people’s earnings from wages and investments plus untaxed amounts, such as from health coverage. Such additions nearly double the income of people in the lowest tier and add about 20 percent for those in the highest tier.

The results of the research revealed the remaining steep progressive nature of the U.S. income tax system. The Wall Street Journal reported, “For 2018, households in the top 20% will have income of about $150,000 or more and 52% of total income, about the same as in 2017. But they will pay about 87% of income taxes, up from about 84% last year.”

Conversely, the lower 60 percent of households, who have income up to approximately $86,000, receive about 27 percent of income. This group will pay no net federal income tax in 2018, and were only responsible for paying 2 percent of it in 2017.

The Tax Policy Center also confirmed that the earners in the top quintile of taxpayers make $150,000 to $100 million and up. Approximately one million households in the top one percent — those who earn over approximately $730,000 — will pay 43 percent of income taxes, up from 38 percent last year.

The share of income taxes paid by the top 5 percent will rise despite those in that tier being the largest beneficiaries of the recently passed tax cut, both in dollars and percentages, according to Roberton Williams, an income-tax specialist with the Tax Policy Center.

Income taxes are negative for 77 million households in the bottom two tiers because Congress has in recent decades chosen to funnel benefits for lower earners through the income tax rather than other channels such as federal programs.

The share of income tax paid by people in those tiers was lowered by the recent tax reform, in part because it nearly doubled the standard deduction and expanded the tax credit for children under the age of 17. People in the lower tiers pay other federal taxes, such as for Social Security and Medicare.