Some embodiments include an assembly having a CMOS tier. The CMOS tier includes a PMOS deck and an NMOS deck, with the decks being vertically offset relative to one another. The PMOS deck has p-channel transistors which are substantially identical to one another, and the NMOS deck has n-channel transistors which are substantially identical to one another. An insulative region is between the PMOS deck and the NMOS deck. The CMOS tier has one or more circuit components which include one or more of the n-channel transistors coupled with one or more of the p-channel transistors through one or more conductive interconnects extending through the insulative region. Some embodiments include methods of forming assemblies to comprise one or more CMOS tiers.