I agree with Suzanne, they are all different and it's probably worthwhile to draw a geographic boundary and call every facility within it. I wouldn't take the first answer I get, however. Some will tell you they only do referrals out of the management office to selected agents, but that is often less than fully true. I just helped a friend get into a very large facility and the rules there allow homeowners to buy & sell their units through any broker they want, same as any other home. There are sign restrictions and prohibitions, so you may run up against that. I drove around a facility with my friend and found no signs, but later discovered that there were over a dozen units for sale. Management didn't allow For Sale signs because the presence of the sign has a negative emotional impact on the other residents (understandable...). Try a few calls, you may end up farming those homeowners the way you do any other potential seller.