Social Insurance Tax Revenues Have Climbed Steadily

Since 1968, social insurance tax rates, which include Medicare, Medicaid, and Social Security taxes, have been the second-highest portion of overall federal tax revenue. If social insurance taxes are raised even further, they could easily overtake income taxes as the greatest share of federal revenue.

Revenues, by Source, as a Share of Gross Domestic Product for 1957–2007

Source: Congressional Budget Office, Long-Term Budget Outlook, December 2007.