Like every other answer to a tax question it depends. I've e-filed for deceased clients that went fine and I had some that could not e-file. Depends on if it is a single return or a joint surviving spouse. If they are getting a refund or not (Form 1310). How did you answer the will/executor questions usually causes it to not e-file. I always complete the return as if I will e-file it then see if there are any errors preventing it.