AFFORDABLE CARE ACT TAX. Short Term health insurance is health insurance outside of the Affordable Care Act ("Obamacare"). It does not include all ten of the minimum essential benefits of Obamacare and it does not cover pre-existing conditions. To learn more about the tax, its exemptions, and how to calculate the affordability of short term health with the tax, see here. To learn more about the differences between Short Term health insurance and Obamacare, see here.