During each two-year congressional session, representatives and senators introduce approximately 25,000 bills, but only about 2,500 actually become laws. Concerned about arbitrary laws, the Framers of the Constitution set a multi-step legislative process in place, allowing for more consideration and debate than a faster process would provide.

Introducing and Numbering the Bills

Any member of Congress may introduce a bill by providing a draft to the clerk of the appropriate chamber. The clerk assigns a number to each bill, beginning with "H.R." for bills in the House of Representatives or "S." for bills introduced in the Senate, followed by sequential numbers that begin again with one at the start of each session. At this point, either bills are placed on the chamber's legislative calendar for floor action, or they are referred to the appropriate committees.

Beginning Committee Action

Once a bill goes to the appropriate committee or jointly referred if more than one committee has authority over the proposed actions, it usually goes to a subcommittee. Members and their staff conduct research on the purpose and effects of the proposed law, often conducting hearings to gauge support or opposition for the law, as well. The subcommittee adds amendments or "marks up" the bill, as they deem appropriate before taking action. They may table it, which means the proposal effectively dies, or they may "report out" the revised bill. Reporting out sends the proposal back to the whole committee with a report that includes the purpose and content of the bill and an estimate from the Congressional Budget office of the potential costs of the law and its effects on the federal budget. At this point, the committee may table the bill or order it reported to the larger chamber of Congress.

Taking Floor Action

The House Rules Committee or the Senate leadership now places the proposed law on the legislative calendar for floor action. Following debate and a vote, approved bills go to the other Congressional chamber, where they generally follow the same steps through subcommittees and committees before coming to the floor of the second chamber for a vote.

Coming Together in Conference Committee

If the differences between the House and the Senate versions of the bill are minor, the legislation returns to each chamber for "concurrence," or approval. For major disparities, the bill goes to a conference committee made up of members from both the House and the Senate. The conference committee members work to resolve the differences before sending a final version to both houses for approval. Both the House and the Senate must approve the revised bill for it to become law. If approved, the bill goes to the executive branch for presidential action.