Based on the information provided in your question, I am thinking that the reason the Standard Deduction of $26,600 is better than Itemized Deductions for your return has to do with the 7.5% floor applied to Medical Expenses. The Medical Expenses reported on Schedule A are reduced by 7.5% of your income to arrive at the deductible portion.
For example, if your Adjusted Gross Income is $100,000 and your out of pocket medical expenses are $15,979, this amount is reduced by $7,500 [$100,000 x 7.5%= $7,500]. Therefore, your deductible medical expenses on Schedule A would be $8,459 [$15,979 - $7,500 = $8,459].
If this doesn't apply to your situation, please comment below so that I can assist you further.
