Yes, it can be done, but not usually with a thin cover garment in hot weather.

The problem with the G17 (and other full-size service-style autoloaders) is the length of the grip. If holstered pointing straight down, the grip pokes rearward, printing against the cover garment. Making sure your holster is set-up to angle the weapon muzzle-to-the-rear (forward cant) will effectively "shorten" the grip, minimizing any printing at the rear, with the trade-off of a different grip angle that has to be managed during the draw. Picture the butt end of the grip being directly over the muzzle-end of the barrel when the weapon is holstered; this is ideal for concealment, but less than optimal for the draw stroke, and takes some getting used to.

You'll also need a holster that sucks that big double-column-magazine-holding grip frame in tight against your body.

I live in a cooler part of the country, so my cover garments can be thicker or layered without looking too out-of-place for 8-9 months of the year. During mid-summer, though, the G17 is a tough choice for concealment.

Great advice, above.

I have successfully carried similar sized pistols, and have learned that a forward cant with the grip as near to vertical as is practical is the key. Barrel length is not that much of a factor.

What you will discover soon enough is that carrying a handgun is uncomfortable, period, and the bigger the gun the more uncomfortable it is. You pretty much have to carry IWB, if not wearing a cover garment, and the hybrid (leather and kydex) holsters are the most comfortable in my opinion. You have to have a good belt and cinch it up tight, which over the course of a long day gets very uncomfortable. Then, there is the weight factor, when fully loaded - it gets heavier as the day wears on.

You can get used to the discomfort, if you are genuinely committed to concealed carry, but most folks don't. I have a drawer full of holsters and a variety of carry type handguns, and still have not found the perfect CCW...but then, I like to buy guns and make holsters.

I have carried a beretta 92 IWB for 2.5 years with no issues... And yea, in the summertime with just one shirt on too. So, it can easily be done. I can only get away with it in the 3 o'clock position, though.

I use a comptac polymer holster. I do not personally care for those holsters with the huge side of leather that sticks up against your skin. It's hot enough down here in Tx without wearing that to make ya sweat in that one spot even worse, IMHO.

Thanks for the help guys. I ordered the Galco KingTuk IWB holster for it after many good reviews so I'm going to see how it goes. This will be my first carry weapon but I'm a gun enthusiast so if it's a little more than I'm comfortable with then it just gives me a good excuse to buy a 19. Haha... Thanks again for all your help.