Is the Belgium Museum Pass available for Americans or only citizens of Belgium? If it is not available for Americans is there another pass I can order online?
The website says you need a valid Belgian address to buy the pass online. To buy in person you need a valid EU address.
I got the same information (in French) when I wrote to the museumPASSmusees customer service email address. Only residents of Belgium can buy a Belgian museum pass online, and only people with a valid address in the EU can buy a museum pass in person at the subset of participating museums that sell museum passes.