With year-end coming up fast, it’s time to get serious about spending every penny of your FSA (flexible spending account).

Using an FSA can be beneficial for your budget. You get to use pre-tax dollars – meaning money out of your paycheck that you don’t have to pay income taxes on – to fund it. In fact, money funneled into an FSA lowers your taxable income and your total taxes, too. Plus, you can use it for a wide variety of health-related expenses, including insurance deductibles and copays, prescriptions, dentist visits, and eye exams.

FSAs can’t be used to pay health insurance premiums.

Even if you’re a basically healthy person, you have some medical expenses during the year, so it makes sense for almost everyone to sign up for an FSA if it’s available.

But there’s a big catch: Any money you don’t spend disappears at the end of the year. If you don’t use it, you lose it. Permanently.

There’s a simple way to avoid that. Think about your common medical expenses during the year. Estimate how much they cost. And don’t fund your FSA for more than you reasonably think you’ll spend in one year.

If you do find yourself with money left in your FSA now, here are just some of the things you can spend it on, according to the IRS:

  • Birth control
  • Supplies for testing blood sugar
  • Bandages
  • First aid kits
  • Acupuncture treatments
  • Contact lenses and contact lens solution
  • Eyeglasses
  • Reading glasses
  • Chiropractors
  • Walkers, canes, and crutches
  • Certified service animals
  • Prescription sunglasses
  • Sunscreen SPF 15 or higher
  • Invisalign
  • Nasal spray, nasal strips, and Neti pots

You have until December 31st to spend your FSA down to zero (unless your employer offers up to a 2½ month grace period – check before you wait). Start stocking up on sunscreen and bandages today, so you don’t lose a dime. And if you are scrambling to spend the balance, stash less in your FSA next year.