A flexible spending account (FSA) is a special type of account used to pay for health expenses. With this type of account, you (along with your employer, in some cases) can make contributions up to a maximum of $2650 in 2018 (the cap on contributions changes every year). You decide how much you will contribute at the beginning of the year and cannot change it thereafter. The money in an FSA is front-loaded, meaning you may use the full amount immediately at the beginning of the year, even though the full amount has not yet been withheld from your paycheck. You must use the funds in the FSA during the calendar year (some employers allow you to use a previous years funds through March of the following year), or you will lose the funds. You may only use the funds on IRS defined allowable expenses, so make sure to check that your expenses qualify.