what are the biggest sources of revenue for the federal government
United States federal budget During FY2016, the federal government collected approximately $3.27 trillion in tax revenue, up $18B (billion) or 1% versus FY2015. Primary receipt categories included individual income taxes ($1,546B or 47% of total receipts), Social Security/Social Insurance taxes ($1,115B or 34%), and corporate taxes ($300B or 10%). Other revenue types included excise, estate and gift taxes.[1]