Are health insurance premiums part of the unreimbursed medical expenses?

Yes. Any medical expenses you pay from your own pocket (post-tax), including health insurance premiums, can be included as unreimbursed medical expenses. However, if your health insurance premiums were paid through your employer, chances are that they were paid pre-tax and aren't deductible. Please check with your employer's benefits coordinator if you're not sure if your premiums are paid with pre-tax or post-tax dollars.