Even if line 1h is zero because there is no excess HA, line 1a should still be $16,970. Even subtracting the deductible portion of SE tax attributable to the $16,970 should be more than $15,000.
It sounds like Turbotax is subtracting the entire deductible portion of SE tax, and not just the deductible portion attributable to the wages. I'm not sure that is correct, but I will need to do more research at home. I don't see it directly covered in either publication 590-A or 517.
