You did it wrong. Just always estimate just above the Medicaid threshold (assuming you legitimately don’t think you’ll make much in the year). Then you get the maximum subsidy, which might even make a Bronze plan completely free. If you end up making less at the end of the year, and really should have been on Medicaid, nothing gets clawed back. If you end up making more than estimated, you just have to pay back some of the subsidy.

Well, there's six grand I'll never get back. At least I know for the future.