"If a single person elects to withhold $5000 for child care expenses and gets married to a non-working spouse, the $5000 would become taxable. If this person did not submit claims by the required date, the $5000 would be forfeited but taxes would still be owed on the amount." Oooh. Looks like you'll have to pay taxes on that $3000, too. Didn't know that. Too bad.