When a member of the House or Senate supports a pending bill, but is not the primary sponsor, they sign their name onto the bill as a cosponsor to illustrate their support
Any of the additional members of a legislature who show their support for a piece of legislation proposed by its sponsor by signing the bill before it is introduced
A legislator who joins with the primary sponsor to guide a bill or resolution through the legislative process in the opposite chamber A cosponsor must be a member of the opposite chamber from the one in which the bill was filed
Once one member introduces a bill, other members may show their support by putting their names on the bill as a cosponsor In general, a bill's sponsor wants as many cosponsors for the bill as possible to give the bill a greatly likelihood of being passed