Medical expenses that were paid by the health insurance company, are not deductible as an itemized medical expense deduction.
See the following from IRS Publication 502:
You can include only the medical and dental expenses you paid this year, regardless of when the services were provided. (But see under Whose Medical Expenses Can You Include, for an exception.) If you pay medical expenses by check, the day you mail or deliver the check generally is the date of payment. If you use a “pay-by-phone” or “online” account to pay your medical expenses, the date reported on the statement of the financial institution showing when payment was made is the date of payment. If you use a credit card, include medical expenses you charge to your credit card in the year the charge is made, not when you actually pay the amount charged. Decedent
If you didn't claim a medical or dental expense that would have been deductible in an earlier year, you can file Form 1040X, Amended U.S. Individual Income Tax Return, for the year in which you overlooked the expense. Don't claim the expense on this year's return. Generally, an amended return must be filed within 3 years from the date the original return was filed or within 2 years from the time the tax was paid, whichever is later.
You can't include medical expenses that were paid by insurance companies or other sources. This is true whether the payments were made directly to you, to the patient, or to the provider of the medical services.