Yes you can.  FAR 32.703-3 Contracts crossing fiscal years gives you the authority.  

      (a) A contract that is funded by annual appropriations may not cross fiscal years, except in accordance with statutory authorization (e.g., 41 U.S.C.6302, 31 U.S.C.1308, 42 U.S.C.2459a, 42 U.S.C.3515, and paragraph (b) of this subsection), or when the contract calls for an end product that cannot feasibly be subdivided for separate performance in each fiscal year (e.g., contracts for expert or consultant services