If you are not self-employed you will deduct health insurance payments on Schedule A Itemized Deductions.
If you are self-employed you may deduct your health insurance payments as a business expense on Schedule C. This link to the TurboTax help page Deducting Health Insurance Premiums If You're Self-Employed has information that you may find useful.
Has the calculation for the self-employed health insurance deduction changed? Last year it appeared on Form 1040, Schedule 1, Section II, Line 29. This year (2019) it appears on Form 1040, Schedule 1, Part II, Line # 16 but is only $5. My premiums were much, much more than that. We have received a 1095-A form from healthcare.gov, and are self-employed. Has anyone else has this happen?
The self-employed health insurance deduction is calculated the same as last year.
It will appear on Schedule 1, line 16 and carry over to line 8a on your 1040.
It sounds like your deduction might be limited this year, because of your self-employment income. The deduction CANNOT exceed the earned income from your business. So, for example, if you have a loss you cannot take the self-employment Health Insurance deduction.
Here is a link that has more details regarding the deduction: Self Employed Health Insurance Deduction
Unused Self Employed Health Insurance amounts will carry over to your Schedule A, itemized deductions.