A Flexible Spending Account is designed to take advantage of Section 125 of the IRS tax code. It allows you to pay certain qualified expenses on a pre-tax basis, thereby reducing your taxable income. You determine the amount of money per plan year to put into your account. The funds in the account can be used to pay for eligible medical expenses like deductibles, co-payments, prescription drugs, and other expenses not covered by your health insurance plan like dental or vision expenses. Funds allocated to a Health FSA must be used during the plan year or lost.