Surprisingly, only 16 percent of American workers contribute the right amount to pre-tax flexible spending accounts (FSA), according to the 2012 Aflac WorkForces Report. As the end of the year approaches, you may realize too late that you've exceeded your annual FSA contribution, creating unanticipated post-tax expenditures. Or you may have underused your FSA dollars, potentially leaving valuable unused funds on the table.

If you've contributed too much to your FSA account and have funds remaining:

1. Schedule annual check-ups with all physicians. Along with your primary care physician, check off visits with important specialists (optometrist, dentist, dermatologist, gynecologist and so on).

2. Don’t forget about eye care/medical aids. Assess whether you need an additional pair of eyeglasses, prescriptive sunglasses, contact lenses or even orthotic shoe inserts and/or other eligible medical aids.

3. Consider purchasing low-cost health care items. Examples of often overlooked FSA-eligible items for year-round or emergency use include first-aid kits, contact solution, thermometers, neck/wrist/joint braces, aspirin and other pain relievers.

4. Ask your employer about unique FSA offerings. Find out whether Lasik eye surgery, massages, acupuncture treatments and other unique procedures or treatments are included in your FSA plan.

If you've exhausted your FSA funds before the end of the year:

1. Keep all receipts. Employees may be able to present health care expenses that weren’t covered by an FSA to tax accountants for 2012 tax deductions.

2. Calculate out-of-pocket costs. Determine what you accrued beyond your allotted FSA amount in order to make smart adjustments to your 2013 FSA during your employer’s open enrollment period.

3. Meet with HR managers or benefits decision makers. Make sure to be as informed as possible about all FSA policy options prior to making benefits elections.