First, get the 1095-A from him.
When you get that, is ONLY your daughter listed in Part 2? If there is more than one person, then look Part 3, column "C". Is there anything in that column?
If there is more than one person and there is also something in column "C", then you need to discuss with your ex how to "allocate" the 1095-A. Generally the best OVERALL result is to allocate 100% to one person (ideally, the one with the lowest poverty percentage). If it can't agree, it is divided by the number of people on the 1095-A (for example, if the 1095-A covers 3 people, you would enter 33% and he would enter 67%).
When you enter the 1095-A into TurboTax, enter the full amount, and on the screen immediately after that, it will ask if the 1095-A was shared with somebody that is not on your tax return, then you would enter the allocated percentage.
As for his Social Security Number, the 1095-A may show it, but it may have a 'cut off' version of it. You should be able to get his Social Security Number from your prior tax returns. Do you have access to those?
As for you paying 27%, that could get tricky to determine that, depending on the circumstances. I recommend first getting the 1095-A, determine the allocation percentage (if applicable) and enter all of that in your tax return. Once you do that, come back and I can try to help you with that, once I know the details of the situation.
