Working for yourself, the health insurance you pay for yourself, your spouse, your dependants and a child under 27 comes off your income - but not for any month you could have joined a subsidized health plan through an employer, yours or your spouse's, a dependant's or such a child's, even if you did not join. The month is judged on its own, and long-term care is judged separately. Medicare premiums you pay voluntarily count.

The deduction cannot be more than the business earned: its net profit, less the deductible half of the self-employment tax and any SEP, SIMPLE or solo 401(k) contribution made for you from it. Long-term care premiums count only up to the year's limit for your age. Form 7206 is needed if you had more than one source of self-employment income, file Form 2555, or are counting long-term care premiums; otherwise the worksheet in the Form 1040 instructions does.