It happened to me two weeks ago. It seems that your clients somehow "played around with the marketplace" and got registered, my clients, both retired, told me they were searching in the website and it looks somehow got enrolled. I would never imagined they did that because I know them for years. But I called them and they explained to me what they did. But look at it this way, it is better this way because before they accepted the return to later retained the refund until the client sends the 8962. This way, there will be no delays or less delay. Somebody says before, ask them for the 1095 even if it is blank and you will be fine. Thanks