Learn about the prescription requirement for over-the-counter medications with a Flexible Spending Account. Flexible Spending Account (FSA) holders know that their benefits can cover qualifying medical expenses and services, but few are aware that over-the-counter (OTC) medications are eligible as well. Since January 1, 2011, some over-the-counter (OTC) items require a prescription to be reimbursed under an FSA. This strictly applies to products containing medicine including Advil, Tylenol or Claritin. Insulin is excluded from the Rx requirement.