For a bill to become a law, it must be passed by both the House and Senate in identical form. Often the second chamber will adopt a different version of the bill, adding its own amendments. This new version is then returned to the first chamber for consideration. If the amended legislation is not acceptable, a conference may be requested.

Conferees from the House and Senate attempt to reach agreement on a compromise bill. If they succeed, a report is issued that is submitted to both chambers. The compromise bill must be voted on as is, with no further amendments.