Well, not all of it, but quite a bit. Rob Coppinger has some thoughts on the issue of ISS downmass requirements, which is something that doesn't get as much attention as the launch payload. Once Shuttle goes away, we lose an awful lot of downmass capability, at least in theory, though I don't think we've been returning all that much in it lately.
There is a huge cost with having no down mass for the Station. All of the hardware was designed with the intent of being R&R and returned to the ground for repair. There is currently a CR at the Space Station Program Office to address the retirement of the Shuttle. This CR is the hundreds of millions of dollars to buy new spare components because the current hardware will not be returned for repair.