What if I have an expense late in the year, and don't get the bill until the following year? How do I file the claim?

An FSA claim is eligible for reimbursement in the year in which it is “incurred.” An eligible expense is considered “incurred” on the date the service or treatment is provided, not on the day you pay for it. If the service or treatment will extend beyond the end of the year, only expenses incurred during the plan year for which you are contributing to your account will be eligible for reimbursement in that plan year. If you have FSA accounts in both years, you will file part of the claim against one year’s account and part against the next year’s account.