Yes, they do come deeper with cabinet shops that do more custom work (I didn't know if you were asking whether they come deeper or shallower than 24", so I am going to assume you meant deeper). But what is more commonly done is to have standard 24" deep base cabinets, and pull them out from the wall several inches to give you deeper countertop space. I think if the base cabinets are too deep, i.e. deeper than 24", you will have more trouble accessing things in the back. But it's quite nice to have a deeper countertop. Also, if you are pulling the base cabinets out a few inches, it is recommended you also have deeper uppers than the standard 12". I will link a thread on this topic.

Here is a link that might be useful: Thread about Deeper Cabinets

Thank you for the replies. I should have stated that I am trying to squeeze in an island instead of replacing my peninsula, so I was thinking of shallower cabinets (just where my desk is now). I was hoping I'd overlooked this option when looking at sites like Kitchenmaid.

Might have looked crazy anyhow.

Not crazy at all!

Yes, you can get shallower cabinets. Either base cabinets made shallower or use a 30" high wall/upper cabinet and add a 4.5" or so toekick under it to make it the standard 34.5" tall base cabinet. Wall cabinets all come in 12" depths and some cabinetmakers will make them 14", 15", or deeper (I have a mix of 12" and 15" deep upper cabinets). Do remember, though, that the counter will be 1.5" deeper (the overhang).

You might also consider putting in a 12" deep tall cabinet with stationary (but adjustable) shelves for pantry storage in place of the desk. 12" deep shelves are deep enough for the vast majority of pantry items as well as most small appliances. No counter needed, either.

I had some custom made to 18 inches. I didn't want the kitchen to feel too crowded.

Good thread. So for those of you that went less than 24, are they on the wall or part of an island? Tell us how shallow base cabinets along a wall look & function? I may have to go 18 or 21 inches in some spots.

I put in a peninsula with an 18" depth -- I needed clearance for the fridge doors to open, so didn't want to squeeze in a standard 24" base cab and have the fridge door bang into it every time I opened it. My cabs are from Medallion, which is only semi-custom, and they didn't have a problem making a shallow case cab. The rest of the kitchen is 24".