Health insurance premiums and Long Term Care Premiums are deducted as an itemized deduction on Schedule A to the extent that they, along with other unreimbursed medical expenses exceed 7.5 percent of your adjusted gross income. Schedule A is not available in TurboTax Free Edition you will have to purchase TurboTax Deluxe if you want to itemize your deductions.
The standard deduction for married filing jointly for 2018 is $24,000 if your itemized deductions do not exceede this amount then there is no tax benefit to itemizing your deductions.