The "Use It or Lose It" Rule
Under current U.S. tax law, unused balances in the Dependent Care Spending Account are subject to forfeiture. If you have a balance left in the account after submitting all claims incurred during the plan year (January 1 – December 31), that balance will be forfeited after the claims filing deadline (March 31 of the year following the plan year). The unused balance cannot be returned to you or carried forward for future use.
It's very important that you plan carefully before you decide how much to contribute to the Dependent Care Spending Account, and that you file your claims by the claims filing deadline: March 31 of the year following the plan year.
For detailed instructions on how to submit claims, see "Paper Reimbursement Claims."