Q:”What happens to an approved Senate bill with respect to an identical House bill? If the House version is defeated, does the bill end?”
This is a great legislative process question. Let me rephrase it: What are companion bills and how do they work?
The usual legislative process is that either the House or Senate introduces a bill, they pass it, it goes to the other chamber, etc. etc. In this process, we’re talking about a single bill
that goes back and forth between the chambers one chamber at a time.
Another common route is that two identical companion bills
are introduced simultaneously. A representative introduces a House bill in the House (e.g. “H.R. 1234”) and around the same time a senators introduces a Senate bill in the Senate (e.g. “S. 5678”). This is useful because both chambers can consider the bill simultaneously, though they may end up proposing different sets of amendments and working up different consensuses.
The bottom line here to remember is that these two bills are, procedurally speaking, entirely separate. That means both have a life of their own, both could bounce back and forth between the chambers until one (or both!) are passed. (Of course, never would Congress actually pass two identical bills.) Both have a life of their own, and a death of their own. If one comes to a vote and is defeated, the other bill lives on. But, say it was the Senate version that was defeated, the House bill is probably not going to come up for a vote because our lawmakers know what will happen in the Senate: it will probably be defeated too.
Typically, the House and Senate will each vote on their own bills with a roll call vote. Then only one of the two bills is pushed forward. That bill goes to the other chamber. Say it was the Senate bill that goes forward: it then goes to the House. If the Senate bill remained identical with the House bill after any amendments both chambers may have made to their own bills, the House will then typically approve the vote via voice vote (or unanimous consent in the Senate), where the position of each Member is not kept: they are already on record on their own bill where they took a full vote. If substantial changes were made, they may or may not conduct a roll call vote.
Usually companion bills are identified as “identical” bills on GovTrack. In fact, the Congressional Research Service, an arm of Congress, does the research to keep track of companion bills and GovTrack just makes use of their work to do this.