While MAAX shower doors aren't available in every hardware store, they are carried by Lowes and Home Depot, as of 2015. Menard's and other hardware stores around the country carry some of the shower doors, though Ace Hardware is one chain that doesn't carry the products in all its stores.
In order to pinpoint which hardware stores carry the MAAX shower doors, the company has a store locator on its website. Users can put in their ZIP code and get a long list of the stores in the area that sell the shower doors. Most of the stores are national chain hardware stores, but there are also some local stores carrying the doors.