The final answer I got after several extended conversations with tech support is that Turbotax cannot properly handle health insurance for self-employed individuals that was purchased through the Marketplace. (At least, as in my case, when the AGI is over the limit to receive any premium tax credit.) The advice I was given was to (contrary to instructions) delete the entries on 1095-A and enter the health insurance expense on the Schedule C (as if the insurance wasn't purchased through the Marketplace). The rep suggested that I print the Form 8962 before deleting the 1095-A entries in case the IRS contacted me for it! I filed as directed but this is an unsatisfactory solution in my opinion. I hope Turbotax fixes this deficiency before the next filing season.
