Hi, I just ran across this myself. If the column has 0, you have to find what the second lowest cost of the Silver plan (SLCSP) premiums and enter it in the column. To do this go to the tax tool section of marketplace and it will walk you through a few screens (birthday, household #, zip code, months received) and give you the number. Here is the link: Health coverage tax tool | HealthCare.gov
Good luck! I was surprised about the need for this extra step.
