This IRS article, and this answer on money.se seem to indicate that health insurance premiums are deductible for the self employed. However, turbo tax, when entering this deduction, specifically warns to not include premiums paid on insurance obtained through the ACA.
Which one is correct?
I believe the premiums are deductible, but the computation of the deduction is not necessarily simple. This site and this blog post discuss a problem that arose because, for self-employed individuals, the premium subsidy was dependent on the adjusted gross income, but (due to the self-employed premium deduction), the adjusted gross income was circularly dependent on the premium subsidy. The IRS issued a ruling on how to resolve this dependency, providing two algorithms for computing the deduction.
The fact that the IRS issued a ruling to tell self-employed people how to deduct their ACA premium costs means those costs must be deductible.
It is possible that TurboTax incorporates this ruling, and that's why it's telling you not to include ACA premiums at that particular point. Have you looked through the rest of TurboTax's questions to see if it wants you to enter the ACA premiums somewhere else?
