The maximum amount you may contribute for a year depends on your unique circumstances. You are required to monitor your own contributions to make sure you do not contribute more than this maximum amount. If you do make contributions in excess of the limit, you can request a return of excess contributions up until the April tax-filing deadline. Contact the Hess Benefits Center at Fidelity for details. Any excess amounts not returned to you prior to the tax deadline are subject to both income and excise taxes.