A microelectromechanical (MEMS) system may comprise multiple sensors within cavities of the MEMS system. The operation of different sensors requires different pressures within the respective cavities. A first cavity may be sealed at a first pressure. A through-hole may be etched into a cap layer of the MEMS system to introduce gas into a second cavity such that the cavity has a desired pressure. The cavity may then be sealed by a MEMS valve to maintain the desired pressure in the second cavity.