The IRS apparently noticed that the calculation of MAGI for purposes of the subsidy included deductions of health insurance premiums which were in turn affected by the subsidy - creating a circular definition. Their solution was to create an iterative process to "home in" on the correct amount.
Since this appeared complicated, I called TurboTax and was informed they had implemented the calculation. I purchased it and then dummied in some reasonable numbers to see how it worked.
The first time through it popped up a 'calculating' box before crashing to desktop.
The second time it simply said I owed a lot more taxes and did not carry any amount to the line for self employed premium deductions on the 1040.
So basically it's not working yet.
Does anyone know of a resource that will let me ballpark the deduction amount without doing to by hand?