A general health FSA is the most common flexible spending account. It's an arrangement through your employer that lets you pay for qualified healthcare expenses with tax-free dollars, for yourself, your spouse, and your dependents.

Healthcare costs, copays, prescriptions, dental work, add up over the year. A general health FSA lets you pay for these with pre-tax dollars, lowering your taxable income while covering expenses you're already paying for.

To have a general health FSA, your employer needs to offer it. Self-employed individuals aren't eligible for an FSA at all, regardless of employer. Certain limitations may also apply if you're a highly compensated employee or a key employee.

You fund your general health FSA through payroll deductions, before taxes are withheld. Your employer may also contribute, up to certain limits. (See "General health FSA contribution limits" for details.)

You can access your entire annual election amount starting on day one of your plan year, even if you haven't actually contributed that much through payroll yet. Your employer essentially fronts the money and recoups it through your payroll deductions over the rest of the year.

Whether unused funds carry over to the next year depends on your employer's plan. (See "General health FSA contribution limits" for how carryover and extension periods work.)

There are rules about combining a general health FSA with an HSA or other benefit types. (See "Combining your general health FSA with other benefits.")

See "Eligible expenses for your general health FSA" for the full list, and "Ineligible expenses for your general health FSA" for what's excluded.