Precipitation strengthened HEA based on the Ni-Co-Fe systems have been investigated. By controlling the elemental partitioning between HEA matrix and strengthening precipitate, thermal stability of the strengthening phase can be enhanced in the high entropy FCC matrix. Formation of detrimental high temperature stable phases, such as TCPs, can be associated with the relatively high content of Fe. With careful control of compositions, HEAs can possess stable FCC+L12 microstructures with no TCP phases after long term exposure at elevated temperatures. Due to relatively high content of Fe and Ti, raw materials cost and alloy density of these HEAs can be lower than those of conventional Ni-based superalloys.