Line chart showing the value of each component of federal revenue between 2015 and 2024. The top contributor, by far, was individual income, representing $2.72 trillion of federal revenue in 2024. Social insurance and retirement was in second, with a $1.73 trillion share that same year. And corporate income came in third at $525.91 billion for 2024. Other revenue streams, including estate and gift, excise tax, and customs duties constitute a relatively small share of federal revenue.