A self-employed proprietorship business person can deduct his or her health insurance premium, and this deduction is taken as an adjustment to the your income. This means it is not subject to the usual 7.5% Adjusted Gross Income limitation. However, this is true only for a profitable business.
Whereas, for regular W-2 employed taxpayers, the Health Insurance premium is deducted on Schedule A subject to the 7.5% Adjusted Gross Income limitation. Furthermore, the total amount on Schedule A could be further limited due to Income exceeding certain amounts, (subject to phaseout limitations for high income taxpayers).
In this manner, Health Insurance paid by self-employed taxpayers is granted a more favorable tax treatment.