It is true. Members from both the House of Representatives and the Senate can co-sponsor a bill.
To co-sponsor a bill is to support a sponsor's bill. A sponsor is a senator or representative that presents a bill or an amendment to a bill for consideration. The sponsor is the one who asks their colleagues to become co-sponsors of his/her bill. Therefore, co-sponsors, who can be members from the House of Representatives or the Senate, show their support by adding their names. Those who were listed as co-sponsors at the time of a bill's introduction are known as "original co-sponsors", while those who were added as co-sponsors later on, that is to say after the bill has been dropped, are known as "additional co-sponsors".
