Yes, if your third of the premium is not deducted pre-tax from your paycheck and you pay them out of pocket, you can deduct your payments, if you itemize your deductions on Schedule A.  

Keep in mind medical expenses are subject to a 7.5% floor, meaning only the portion in excess of 7.5% of your Adjusted Gross Income become deductible on Schedule A.

Finally, your medical expenses plus your other itemized deductions still must exceed your standard deduction before they increase your refund (or lower your balance due).

Check out the TurboTax FAQ below for more details on deducting medical expenses:

https://ttlc.intuit.com/replies/4774889