once in a while - now with everyone using the go-cutters there seem to be a few more than used to be-but generally a kit comes with the fabric requirements called for on the pattern- then you have to follow the cutting instructions ... always read about the kit you are interested in- sometimes they do not include the pattern- it may be a kit for a pattern that is free on a particular site-or in a magazine- or in a book which you have to purchase separately. but it is not common for the pieces to be cut out for you-
if you purchase a kit it is always best to lay out all of the fabrics, measure each piece & identify it with the pattern/fabric list before you cut anything---that way if an error has been made & you are short a fabric, or missing one you can contact the place you purchased from right away- also, that way you don't cut something out-only to find further down the road that it was not the correct piece- mistakes do on occassion happen- humans put together kits- so start out organized-knowing what you have to work with...read through the whole pattern before you start.