Concurrence basically means “agreement,” and it is the last step some bills go through in their journey through the legislative branch before they are sent to the executive branch—the president or governor—for a final decision.
The United States Congress is a bicameral legislative body consisting of an upper house (the U.S. Senate) and a lower house (the U.S. House of Representatives). Forty-nine of our 50 states have bicameral legislatures, too—the exception is Nebraska, which has a unicameral or one-house legislature. In a bicameral system, bills must pass both the upper and lower house before they are sent on for executive action. The trick is that they must be passed by each legislative branch in identical form. The two houses typically consider bills independently of each other, often making additions and subtractions in language along the way. Therefore, by the time a bill has passed both houses, there often are differences in the versions each house has approved. These differences must ultimately be ironed out to create one bill that pleases a majority in each house. This is when concurrence is sought.
Let’s say a federal bill was first introduced in the Senate, which passed a version it liked before sending the bill on to the House of Representatives. The House of Representatives then also passes this bill, but not before making some changes. Although in theory the bill has passed both bodies, each passed a different form of it. In our example, the House version of the bill, being the most recent, will sometimes be sent back to the Senate for concurrence, especially if the changes are minor or if there is a rush to get it passed.
If the differences between the two versions of the bill are substantial enough that concurrence seems unlikely to work—or, if concurrence is attempted, but fails (example: the Senate doesn’t like the House’s changes)—legislators from both houses will be assigned by leadership to a conference committee to reconcile the differences between the two versions of the bill, which then goes back to both houses for a final vote. If the committee members are unable to come to a compromise version of the bill before the end of the legislative session, the bill dies.