A flexible spending account (FSA) is one of several tax-advantaged financial accounts that can be set up through a cafeteria plan adopted by your employer.

A medical FSA is the most common type of flexible spending account, and allows you to set aside a portion of your earnings to pay for qualified expenses, most commonly for medical costs, such as doctors, dentists, and optometrist copays.

It should be noted that funds not used by the end of the plan year are lost to the employee, known as the “use it or lose it” rule, unless your employer has a rollover provision.