Cycles viewport doesn't match render

I’m having an issue where the scene looks great from the camera view, but when I render the shot, one of my meshes is way messed up. See the images below. The first is how it looks in the camera view, the second is the render. The one I’m having issues with is the very top layer. All the meshes in this shot are completely flat, so I can’t see any reason why the edges are being cut off in the final render. Any ideas?

you have a subsurf modifier with render on but viewport off.

Thanks. I must of hit something and didn’t realize it.