That is a great question and there are some things to keep in mind.
In most cases it is always better to use Tax Free funds to pay for your medical expenses. The biggest reason is that for medical expenses to even go onto your Schedule A Itemized deductions, they have to be greater than 7.5% of your income and only the portion that is over that is allowed as the deductible amount. So you already lose 7.5% of the benefit if you use the deduction versus the HSA.
If you know that you will have a large amount of total Itemized Deductions, that may be when you would want to use the medical to boost the amount. Another area to remember, is that if you are hit with AMT (Alternative Minimum Tax) this could have a huge impact on your itemized deductions as well.
The great thing about using TurboTax is you will enter the information into the software and it will tell you if it is better to itemize or not, but if you used the HSA before filing, you would not be able to include those medical expenses paid for via the HSA.
To be absolutely sure on what is best for your situation, more information and a general idea on if you have the same high expenses year over year or if this is a one time expense.
Basics of Health Savings Accounts
Standard Deduction versus Itemized
