A Flexible Spending Account (FSA) is a special account that allows employees to set aside pre-tax money for eligible medical expenses. This means that the money you contribute is deducted from your paycheck before taxes, which can lower your taxable income. FSAs can be used for various expenses, such as doctor visits, prescription medications, and dental care. Employees typically decide how much to contribute to their FSA at the beginning of the year. However, it's important to note that any unused funds may be forfeited at the end of the plan year, unless the employer offers a grace period or a carryover option.