I have never carried concealed. Never seen the need to. I have lived in Seattle, San Francisco, New York, DC, with no need to carry, and spent a lot of time in other big cities. I have also on occasion spent a lot of time in rural areas. If I need to be armed in the line of duty it was always open carry (Miami, Chicago, and others)

However I have had several coats over the years that were perfect for carrying in a holster on a belt. They had large pockets with slits inside them that were wide and could easily allow a gun to be drawn. I currently have an Air Force parka that I bought while stationed in Salt Lake City in 79-81 that has the same arrangement. I can actually reach though the pockets to get my ID out of my breast pocket without any problems. Years ago when I was on shore patrol at Coast Guard Base NY (GINY to those that have been there) on the rare occasions when we were armed we had jackets that had a similar arrangement.

You could probably find a parka at a Army Navy surplus that has pockets like that. Or police uniform stores would also have coats like that. All the NYPD cops had them.