A microelectronic device comprises pillar structures extending vertically through an isolation material, conductive lines electrically coupled to the pillar structures, contact structures between the pillar structures and the conductive lines, and interconnect structures between the conductive lines and the contact structures. The conductive lines comprise one or more of titanium, ruthenium, aluminum, and molybdenum. The interconnect structures comprise a material composition that is different than one or more of a material composition of the contact structures and a material composition of the conductive lines. Related memory devices, electronic systems, and methods are also described.