In an appearance on NBC's "Meet the Press" program, the Democrat said the legislation is the product of compromise with Republicans. No Republicans voted for the House version and only three Republicans have signed on to the Senate version.
"We had a group of Republican senators in a room, and we worked hour after hour and, by the way, that door was open to every Republican in the Senate to come into that room and go through this bill line by line by line," McCaskill said.
The Senate version of the economic stimulus will cost $827 billion, or $7 billion more than the House-approved version.
The Senate plan has more tax breaks than the House version. The Senate version of the bill would also double the tax credit for first-time home buyers to $15,000.
"If we don't move the housing stock, this whole thing is going to be slower and more painful than it needs to be," McCaskill said of the national recession.