Everyone seems to do it a little differently. Personally, as a homeowner, I would have asked for, and paid for, a fully tiled floor.
Shims are used and some cabinet installers use plywood rips as shims if the gap is large.
By the time they attach the cabinets to the walls and floor, it's strong enough to hold the granite, etc.

They did fully tile the area for dishwasher, frig, and possible slide-in stove, right?

Hi Annz, thanks for responding. As a homeowner, yes, that was what I was expecting but my GC has repeatedly said that their practice has always been to shim (thus leaving the borders empty). I'm unhappy with that, but I guess that's not much I can do at this point (they've installed most of the cabinets yesterday). Yes, they did tile the dishwasher, fridge, and range areas... as an afterthought! They had to get the tile guy to come back and do it, since those areas were left empty before. The guy did a lazy attempt at it (the tiles in the area are laid horribly and the grout in the area isn't sealed like the rest of the areas) but since I won't be able to see them after the appliances are in... it always seems like picking the right battles with these guys!

You're cutting the checks, you get to decide how it's done. If you want tile under your cabinets, (and I definately would) then you call your GC and tell him that. This should have been spelled out in your contract with him, that way there wouldn't have been any issues with this being considered an "upgrade". And, I'd want any poorly done tiling redone at no charge. You're NOT paying for a pro to do a poor tile job. That can be done DIY without paying for the priviledge! :)

In all the kitchens I've done, I've NEVER had a contractor use only shims to get the cabinets to be the same height as the finished flooring. If the homeowner didn't want to have the finished floor under the cabinets, then plywood of the same thickness was always laid under the cabients to make it an easier transition. Now, that assumes that your floor IS level. If it's not level, then using minimal shims on top of the plywood (or wood or tile, etc.) can be done to get those cabinets level. However, the proper prep work for the floor wasn't done to get it level if you have to use more than a couple of shims.

Our contract does include tile in the entire kitchen. The GC did buy enough material to cover all of it, so now we have 2 cases of tiles sitting around that will not be used ;(
I wish I had talked to you guys earlier, before all the cabinets were installed in! They are already a month behind from their original schedule, and I'm hoping that the cabinets are stable enough with just the shims for support in the back! What do you think, in terms of long-term stability?

If it was in the contract I would insist the GC do it right. Let him take out the cabinets and have the rest of the tile done properly. Then he needs to put the cabinets back. He can't argue "its always done this way" if its in the contract! This type of shims or plywood under cabinets is common but not everyone likes this method.

As a general rule I won't allow "shimmies" in my house. You never know where they've been or what they're up to under there.

I must admit the title of this thread took me by surprise at first! Where I am from "shimmies" are undergarments! (actually under-shirts with 'shimmy' taken from the word 'chemise') It would have been interesting to see cabinets having only undergarments to hold them up! Maybe not!

Haha I've never heard of shimmies before this remodeling project either! "Shimmies" are bits of wood used to level off cabinets... and it's getting apparent on this thread that I'm getting gypped. I envisioned them to use solid wood in place of where there is no tile, but they used only shims to boost up the back of the cabinets.
Debrak_2008, you say this is a common method? I will agree that I am part of the camp that does NOT like this method, but do you think they'll hold up in the long run?